Dermatopathology

The Diagnosis: Lichen Planus Pemphigoides

Lichen planus pemphigoides (LPP) is a rare acquired autoimmune blistering disorder with an estimated worldwide prevalence of approximately 1 in 1,000,000 individuals.¹ It often manifests with overlapping features of both LP and bullous pemphigoid (BP). The condition usually presents in the fifth decade of life and has a slight female predominance.² Although primarily idiopathic, it has been associated with certain medications and treatments, such as angiotensin-converting enzyme inhibitors, programmed cell death protein 1 inhibitors, programmed cell death ligand 1 inhibitors, labetalol, narrowband UVB, and psoralen plus UVA.^3,4

Patients initially present with lesions of classic lichen planus (LP) with pink-purple, flat-topped, pruritic, polygonal papules and plaques.⁵ After weeks to months, tense vesicles and bullae usually develop on the sites of LP as well as on uninvolved skin. One study found a mean lag time of about 8.3 months for blistering to present after LP,⁵ but concurrent presentations of both have been reported.¹ In addition, oral mucosal involvement has been seen in 36% of cases. The most commonly affected sites are the extremities; however, involvement can be widespread.²

The pathogenesis of LPP currently is unknown. It has been proposed that in LP, injury of basal keratinocytes exposes hidden basement membrane and hemidesmosome antigens including BP180, a 180 kDa transmembrane protein of the basement membrane zone (BMZ),⁶ which triggers an immune response where T cells recognize the extracellular portion of BP180 and antibodies are formed against the likely autoantigen.1 One study has suggested that the autoantigen in LPP is the MCW-4 epitope within the C-terminal end of the NC16A domain of BP180.⁷

Histopathology of LPP reveals characteristics of both LP as well as BP. Typical features of LP on hematoxylin and eosin (H&E) staining include lichenoid lymphocytic interface dermatitis, sawtooth rete ridges, wedge-shaped hypergranulosis, and colloid bodies, as demonstrated from the biopsy of our patient’s gluteal cleft lesion (quiz image 1), while the predominant feature of BP on H&E staining includes a subepidermal bulla with eosinophils.² Typically, direct immunofluorescence (DIF) shows linear deposits of IgG and/or C3 along the BMZ. Indirect immunofluorescence (IIF) often reveals IgG against the roof of the BMZ in a human split-skin substrate.¹ Antibodies against BP180 or uncommonly BP230 often are detected on enzyme-linked immunosorbent assay (ELISA). For our patient, IIF and ELISA tests were positive. Given the clinical presentation with recurrent oral and gluteal cleft erosions, histologic findings, and the results of our patient’s immunological testing, the diagnosis of LPP was made.

Topical steroids often are used to treat localized disease of LPP.8 Oral prednisone also may be given for widespread or unresponsive disease.⁹ Other treatments include azathioprine, mycophenolate mofetil, hydroxychloroquine, dapsone, tetracycline in combination with nicotinamide, acitretin, ustekinumab, baricitinib, and rituximab with intravenous immunoglobulin.^3,8,10-12 Any potential medication culprits should be discontinued.⁹ Patients with oral involvement may require a soft diet to avoid further mucosal insult.¹⁰ Additionally, providers should consider dentistry, ophthalmology, and/or otolaryngology referrals depending on disease severity.

Bullous pemphigoid, the most common autoimmune blistering disease, has an estimated incidence of 10 to 43 per million individuals per year.² Classically, it presents with tense bullae on the skin of the lower abdomen, thighs, groin, forearms, and axillae. Circulating antibodies against 2 BMZ proteins—BP180 and BP230—are important factors in BP pathogenesis.² Diagnosis of BP is based on clinical features, histologic findings, and immunological studies including DIF, IIF, and ELISA. An eosinophil-rich subepidermal split typically is seen on H&E staining (Figure 1).

Direct immunofluorescence displays linear IgG and/ or C3 staining at the BMZ. Indirect immunofluorescence on a human salt-split skin substrate commonly shows linear BMZ deposition on the roof of the blister.² Indirect immunofluorescence for IgG deposition on monkey esophagus substrate shows linear BMZ deposition. Antibodies against the NC16A domain of BP180 (NC16A-BP180) are dominant, but BP230 antibodies against BP230 also are detected with ELISA.² Further studies have indicated that the NC16A epitopes of BP180 that are targeted in BP are MCW-0-3,² different from the autoantigen MCW-4 that is targeted in LPP.⁷

Paraneoplastic pemphigus (PNP) is another diagnosis to consider. Patients with PNP initially present with oral findings—most commonly chronic, erosive, and painful mucositis—followed by cutaneous involvement, which varies from the development of bullae to the formation of plaques similar to those of LP.¹³ The latter, in combination with oral erosions, may appear clinically similar to LPP. The results of DIF in conjugation with IIF and ELISA may help to further differentiate these disorders. Direct immunofluorescence in PNP typically reveals positive intercellular and/or BMZ IgG and C3, while DIF in LPP reveals depositions along the BMZ alone. Indirect immunofluorescence performed on rat bladder epithelium is particularly useful, as binding of IgG to rat bladder epithelium is characteristic of PNP and not seen in other disorders.¹⁴ Lastly, patients with PNP may develop IgG antibodies to various antigens such as desmoplakin I, desmoplakin II, envoplakin, periplakin, BP230, desmoglein 1, and desmoglein 3, which would not be expected in LPP patients.¹⁵ Hematoxylin and eosin staining differs from LPP, primarily with the location of the blister being intraepidermal. Acantholysis with hemorrhagic bullae can be seen (Figure 2).

Classic LP is an inflammatory disorder that mainly affects adults, with an estimated incidence of less than 1%.¹⁶ The classic form presents with purple, flat-topped, pruritic, polygonal papules and plaques of varying size that often are characterized by Wickham striae. Lichen planus possesses a broad spectrum of subtypes involving different locations, though skin lesions usually are localized to the extremities. Despite an unknown etiology, activated T cells and T helper type 1 cytokines are considered key in keratinocyte injury. Compact orthokeratosis, wedge-shaped hypergranulosis, focal dyskeratosis, and colloid bodies typically are found on H&E staining, along with a dense bandlike lymphohistiocytic infiltrate at the dermoepidermal junction (DEJ)(Figure 3). Direct immunofluorescence typically shows a shaggy band of fibrinogen along the DEJ in addition to colloid bodies that stain with various autoantibodies including IgM, IgG, IgA, and C3.¹⁶

Bullous LP is a rare variant of LP that commonly develops on the oral mucosa and the legs, with blisters confined on pre-existing LP lesions.⁹ The pathogenesis is related to an epidermal inflammatory infiltrate that leads to basal layer destruction followed by dermal-epidermal separations that cause blistering.¹⁷ Bullous LP does not have positive DIF, IIF, or ELISA because the pathophysiology does not involve autoantibody production. Histopathology typically displays an extensive inflammatory infiltrate and degeneration of the basal keratinocytes, resulting in large dermal-epidermal separations called Max-Joseph spaces (Figure 4).¹⁷ Colloid bodies are prominent in bullous LP but rarely are seen in LPP; eosinophils also are much more prominent in LPP compared to bullous LP.¹⁸ Unlike in LPP, DIF usually is negative in bullous LP, though lichenoid lesions may exhibit globular deposition of IgM, IgG, and IgA in the colloid bodies of the lower epidermis and/or papillary dermis. Similar to LP, DIF of the biopsy specimen shows linear or shaggy deposits of fibrinogen at the DEJ.¹⁷

The Diagnosis: Lichen Planus Pemphigoides

Lichen planus pemphigoides (LPP) is a rare acquired autoimmune blistering disorder with an estimated worldwide prevalence of approximately 1 in 1,000,000 individuals.¹ It often manifests with overlapping features of both LP and bullous pemphigoid (BP). The condition usually presents in the fifth decade of life and has a slight female predominance.² Although primarily idiopathic, it has been associated with certain medications and treatments, such as angiotensin-converting enzyme inhibitors, programmed cell death protein 1 inhibitors, programmed cell death ligand 1 inhibitors, labetalol, narrowband UVB, and psoralen plus UVA.^3,4

Patients initially present with lesions of classic lichen planus (LP) with pink-purple, flat-topped, pruritic, polygonal papules and plaques.⁵ After weeks to months, tense vesicles and bullae usually develop on the sites of LP as well as on uninvolved skin. One study found a mean lag time of about 8.3 months for blistering to present after LP,⁵ but concurrent presentations of both have been reported.¹ In addition, oral mucosal involvement has been seen in 36% of cases. The most commonly affected sites are the extremities; however, involvement can be widespread.²

The pathogenesis of LPP currently is unknown. It has been proposed that in LP, injury of basal keratinocytes exposes hidden basement membrane and hemidesmosome antigens including BP180, a 180 kDa transmembrane protein of the basement membrane zone (BMZ),⁶ which triggers an immune response where T cells recognize the extracellular portion of BP180 and antibodies are formed against the likely autoantigen.1 One study has suggested that the autoantigen in LPP is the MCW-4 epitope within the C-terminal end of the NC16A domain of BP180.⁷

Histopathology of LPP reveals characteristics of both LP as well as BP. Typical features of LP on hematoxylin and eosin (H&E) staining include lichenoid lymphocytic interface dermatitis, sawtooth rete ridges, wedge-shaped hypergranulosis, and colloid bodies, as demonstrated from the biopsy of our patient’s gluteal cleft lesion (quiz image 1), while the predominant feature of BP on H&E staining includes a subepidermal bulla with eosinophils.² Typically, direct immunofluorescence (DIF) shows linear deposits of IgG and/or C3 along the BMZ. Indirect immunofluorescence (IIF) often reveals IgG against the roof of the BMZ in a human split-skin substrate.¹ Antibodies against BP180 or uncommonly BP230 often are detected on enzyme-linked immunosorbent assay (ELISA). For our patient, IIF and ELISA tests were positive. Given the clinical presentation with recurrent oral and gluteal cleft erosions, histologic findings, and the results of our patient’s immunological testing, the diagnosis of LPP was made.

Topical steroids often are used to treat localized disease of LPP.8 Oral prednisone also may be given for widespread or unresponsive disease.⁹ Other treatments include azathioprine, mycophenolate mofetil, hydroxychloroquine, dapsone, tetracycline in combination with nicotinamide, acitretin, ustekinumab, baricitinib, and rituximab with intravenous immunoglobulin.^3,8,10-12 Any potential medication culprits should be discontinued.⁹ Patients with oral involvement may require a soft diet to avoid further mucosal insult.¹⁰ Additionally, providers should consider dentistry, ophthalmology, and/or otolaryngology referrals depending on disease severity.

Bullous pemphigoid, the most common autoimmune blistering disease, has an estimated incidence of 10 to 43 per million individuals per year.² Classically, it presents with tense bullae on the skin of the lower abdomen, thighs, groin, forearms, and axillae. Circulating antibodies against 2 BMZ proteins—BP180 and BP230—are important factors in BP pathogenesis.² Diagnosis of BP is based on clinical features, histologic findings, and immunological studies including DIF, IIF, and ELISA. An eosinophil-rich subepidermal split typically is seen on H&E staining (Figure 1).

Direct immunofluorescence displays linear IgG and/ or C3 staining at the BMZ. Indirect immunofluorescence on a human salt-split skin substrate commonly shows linear BMZ deposition on the roof of the blister.² Indirect immunofluorescence for IgG deposition on monkey esophagus substrate shows linear BMZ deposition. Antibodies against the NC16A domain of BP180 (NC16A-BP180) are dominant, but BP230 antibodies against BP230 also are detected with ELISA.² Further studies have indicated that the NC16A epitopes of BP180 that are targeted in BP are MCW-0-3,² different from the autoantigen MCW-4 that is targeted in LPP.⁷

Paraneoplastic pemphigus (PNP) is another diagnosis to consider. Patients with PNP initially present with oral findings—most commonly chronic, erosive, and painful mucositis—followed by cutaneous involvement, which varies from the development of bullae to the formation of plaques similar to those of LP.¹³ The latter, in combination with oral erosions, may appear clinically similar to LPP. The results of DIF in conjugation with IIF and ELISA may help to further differentiate these disorders. Direct immunofluorescence in PNP typically reveals positive intercellular and/or BMZ IgG and C3, while DIF in LPP reveals depositions along the BMZ alone. Indirect immunofluorescence performed on rat bladder epithelium is particularly useful, as binding of IgG to rat bladder epithelium is characteristic of PNP and not seen in other disorders.¹⁴ Lastly, patients with PNP may develop IgG antibodies to various antigens such as desmoplakin I, desmoplakin II, envoplakin, periplakin, BP230, desmoglein 1, and desmoglein 3, which would not be expected in LPP patients.¹⁵ Hematoxylin and eosin staining differs from LPP, primarily with the location of the blister being intraepidermal. Acantholysis with hemorrhagic bullae can be seen (Figure 2).

Classic LP is an inflammatory disorder that mainly affects adults, with an estimated incidence of less than 1%.¹⁶ The classic form presents with purple, flat-topped, pruritic, polygonal papules and plaques of varying size that often are characterized by Wickham striae. Lichen planus possesses a broad spectrum of subtypes involving different locations, though skin lesions usually are localized to the extremities. Despite an unknown etiology, activated T cells and T helper type 1 cytokines are considered key in keratinocyte injury. Compact orthokeratosis, wedge-shaped hypergranulosis, focal dyskeratosis, and colloid bodies typically are found on H&E staining, along with a dense bandlike lymphohistiocytic infiltrate at the dermoepidermal junction (DEJ)(Figure 3). Direct immunofluorescence typically shows a shaggy band of fibrinogen along the DEJ in addition to colloid bodies that stain with various autoantibodies including IgM, IgG, IgA, and C3.¹⁶

Bullous LP is a rare variant of LP that commonly develops on the oral mucosa and the legs, with blisters confined on pre-existing LP lesions.⁹ The pathogenesis is related to an epidermal inflammatory infiltrate that leads to basal layer destruction followed by dermal-epidermal separations that cause blistering.¹⁷ Bullous LP does not have positive DIF, IIF, or ELISA because the pathophysiology does not involve autoantibody production. Histopathology typically displays an extensive inflammatory infiltrate and degeneration of the basal keratinocytes, resulting in large dermal-epidermal separations called Max-Joseph spaces (Figure 4).¹⁷ Colloid bodies are prominent in bullous LP but rarely are seen in LPP; eosinophils also are much more prominent in LPP compared to bullous LP.¹⁸ Unlike in LPP, DIF usually is negative in bullous LP, though lichenoid lesions may exhibit globular deposition of IgM, IgG, and IgA in the colloid bodies of the lower epidermis and/or papillary dermis. Similar to LP, DIF of the biopsy specimen shows linear or shaggy deposits of fibrinogen at the DEJ.¹⁷

The Diagnosis: Lichen Planus Pemphigoides

Lichen planus pemphigoides (LPP) is a rare acquired autoimmune blistering disorder with an estimated worldwide prevalence of approximately 1 in 1,000,000 individuals.¹ It often manifests with overlapping features of both LP and bullous pemphigoid (BP). The condition usually presents in the fifth decade of life and has a slight female predominance.² Although primarily idiopathic, it has been associated with certain medications and treatments, such as angiotensin-converting enzyme inhibitors, programmed cell death protein 1 inhibitors, programmed cell death ligand 1 inhibitors, labetalol, narrowband UVB, and psoralen plus UVA.^3,4

Patients initially present with lesions of classic lichen planus (LP) with pink-purple, flat-topped, pruritic, polygonal papules and plaques.⁵ After weeks to months, tense vesicles and bullae usually develop on the sites of LP as well as on uninvolved skin. One study found a mean lag time of about 8.3 months for blistering to present after LP,⁵ but concurrent presentations of both have been reported.¹ In addition, oral mucosal involvement has been seen in 36% of cases. The most commonly affected sites are the extremities; however, involvement can be widespread.²

The pathogenesis of LPP currently is unknown. It has been proposed that in LP, injury of basal keratinocytes exposes hidden basement membrane and hemidesmosome antigens including BP180, a 180 kDa transmembrane protein of the basement membrane zone (BMZ),⁶ which triggers an immune response where T cells recognize the extracellular portion of BP180 and antibodies are formed against the likely autoantigen.1 One study has suggested that the autoantigen in LPP is the MCW-4 epitope within the C-terminal end of the NC16A domain of BP180.⁷

Histopathology of LPP reveals characteristics of both LP as well as BP. Typical features of LP on hematoxylin and eosin (H&E) staining include lichenoid lymphocytic interface dermatitis, sawtooth rete ridges, wedge-shaped hypergranulosis, and colloid bodies, as demonstrated from the biopsy of our patient’s gluteal cleft lesion (quiz image 1), while the predominant feature of BP on H&E staining includes a subepidermal bulla with eosinophils.² Typically, direct immunofluorescence (DIF) shows linear deposits of IgG and/or C3 along the BMZ. Indirect immunofluorescence (IIF) often reveals IgG against the roof of the BMZ in a human split-skin substrate.¹ Antibodies against BP180 or uncommonly BP230 often are detected on enzyme-linked immunosorbent assay (ELISA). For our patient, IIF and ELISA tests were positive. Given the clinical presentation with recurrent oral and gluteal cleft erosions, histologic findings, and the results of our patient’s immunological testing, the diagnosis of LPP was made.

Topical steroids often are used to treat localized disease of LPP.8 Oral prednisone also may be given for widespread or unresponsive disease.⁹ Other treatments include azathioprine, mycophenolate mofetil, hydroxychloroquine, dapsone, tetracycline in combination with nicotinamide, acitretin, ustekinumab, baricitinib, and rituximab with intravenous immunoglobulin.^3,8,10-12 Any potential medication culprits should be discontinued.⁹ Patients with oral involvement may require a soft diet to avoid further mucosal insult.¹⁰ Additionally, providers should consider dentistry, ophthalmology, and/or otolaryngology referrals depending on disease severity.

Bullous pemphigoid, the most common autoimmune blistering disease, has an estimated incidence of 10 to 43 per million individuals per year.² Classically, it presents with tense bullae on the skin of the lower abdomen, thighs, groin, forearms, and axillae. Circulating antibodies against 2 BMZ proteins—BP180 and BP230—are important factors in BP pathogenesis.² Diagnosis of BP is based on clinical features, histologic findings, and immunological studies including DIF, IIF, and ELISA. An eosinophil-rich subepidermal split typically is seen on H&E staining (Figure 1).

Direct immunofluorescence displays linear IgG and/ or C3 staining at the BMZ. Indirect immunofluorescence on a human salt-split skin substrate commonly shows linear BMZ deposition on the roof of the blister.² Indirect immunofluorescence for IgG deposition on monkey esophagus substrate shows linear BMZ deposition. Antibodies against the NC16A domain of BP180 (NC16A-BP180) are dominant, but BP230 antibodies against BP230 also are detected with ELISA.² Further studies have indicated that the NC16A epitopes of BP180 that are targeted in BP are MCW-0-3,² different from the autoantigen MCW-4 that is targeted in LPP.⁷

Paraneoplastic pemphigus (PNP) is another diagnosis to consider. Patients with PNP initially present with oral findings—most commonly chronic, erosive, and painful mucositis—followed by cutaneous involvement, which varies from the development of bullae to the formation of plaques similar to those of LP.¹³ The latter, in combination with oral erosions, may appear clinically similar to LPP. The results of DIF in conjugation with IIF and ELISA may help to further differentiate these disorders. Direct immunofluorescence in PNP typically reveals positive intercellular and/or BMZ IgG and C3, while DIF in LPP reveals depositions along the BMZ alone. Indirect immunofluorescence performed on rat bladder epithelium is particularly useful, as binding of IgG to rat bladder epithelium is characteristic of PNP and not seen in other disorders.¹⁴ Lastly, patients with PNP may develop IgG antibodies to various antigens such as desmoplakin I, desmoplakin II, envoplakin, periplakin, BP230, desmoglein 1, and desmoglein 3, which would not be expected in LPP patients.¹⁵ Hematoxylin and eosin staining differs from LPP, primarily with the location of the blister being intraepidermal. Acantholysis with hemorrhagic bullae can be seen (Figure 2).

Classic LP is an inflammatory disorder that mainly affects adults, with an estimated incidence of less than 1%.¹⁶ The classic form presents with purple, flat-topped, pruritic, polygonal papules and plaques of varying size that often are characterized by Wickham striae. Lichen planus possesses a broad spectrum of subtypes involving different locations, though skin lesions usually are localized to the extremities. Despite an unknown etiology, activated T cells and T helper type 1 cytokines are considered key in keratinocyte injury. Compact orthokeratosis, wedge-shaped hypergranulosis, focal dyskeratosis, and colloid bodies typically are found on H&E staining, along with a dense bandlike lymphohistiocytic infiltrate at the dermoepidermal junction (DEJ)(Figure 3). Direct immunofluorescence typically shows a shaggy band of fibrinogen along the DEJ in addition to colloid bodies that stain with various autoantibodies including IgM, IgG, IgA, and C3.¹⁶

Bullous LP is a rare variant of LP that commonly develops on the oral mucosa and the legs, with blisters confined on pre-existing LP lesions.⁹ The pathogenesis is related to an epidermal inflammatory infiltrate that leads to basal layer destruction followed by dermal-epidermal separations that cause blistering.¹⁷ Bullous LP does not have positive DIF, IIF, or ELISA because the pathophysiology does not involve autoantibody production. Histopathology typically displays an extensive inflammatory infiltrate and degeneration of the basal keratinocytes, resulting in large dermal-epidermal separations called Max-Joseph spaces (Figure 4).¹⁷ Colloid bodies are prominent in bullous LP but rarely are seen in LPP; eosinophils also are much more prominent in LPP compared to bullous LP.¹⁸ Unlike in LPP, DIF usually is negative in bullous LP, though lichenoid lesions may exhibit globular deposition of IgM, IgG, and IgA in the colloid bodies of the lower epidermis and/or papillary dermis. Similar to LP, DIF of the biopsy specimen shows linear or shaggy deposits of fibrinogen at the DEJ.¹⁷

The Diagnosis: Porokeratosis Plantaris Palmaris et Disseminata

A 3-mm punch biopsy of the right upper arm showed incipient cornoid lamellae formation, pigment incontinence, and sparse dermal lymphocytic inflammation (Figure), suggestive of porokeratosis plantaris palmaris et disseminata (PPPD). The dermatopathologist recommended a second biopsy to confirm the diagnosis and to confirm that the lesions on the palms and soles also were suggestive of porokeratosis. A second 4-mm punch biopsy of the left palm was consistent with PPPD.

The risks of PPPD as a precancerous entity along with the benefits and side effects of the various management options were discussed with our patient. We recommended that he start low-dose isotretinoin (20 mg/d) due to the large body surface area affected, making focal and field treatments likely insufficient. However, our patient opted not to treat and did not return for follow-up.

Subtypes of porokeratosis, including disseminated superficial actinic porokeratosis (DSAP) and PPPD, are conditions that disrupt the normal maturation of keratin and present clinically with symmetric, crusted, annular papules.¹ The signature but nonspecific histopathologic feature shared among the subtypes is the presence of a cornoid lamellae.² Several triggers of porokeratosis have been proposed, including trauma and exposure to UV and ionizing radiation.^2,3 The clinical variants of porokeratosis are important conditions to diagnose correctly because they portend a risk for Bowen disease and invasive squamous cell carcinoma and may indicate the presence of an underlying hematologic and/or solid organ malignancy.⁴ Management of porokeratosis is difficult, as treatments have shown limited efficacy and variable recurrence rates. Treatment options include focal, field, and systemic options, such as 5-fluorouracil, topical compound of cholesterol and lovastatin, isotretinoin, and acitretin.^1,2

Porokeratoses may arise from gene mutations in the mevalonate pathway,⁵ which is essential for the production of cholesterol.⁶ Topical cholesterol alone has not been shown to improve porokeratosis, but the combination topical therapy of cholesterol and lovastatin is promising. It is theorized to deliver benefit by both providing the essential end product of the pathway and simultaneously reducing the number of potentially toxic intermediates.⁶

Porokeratosis plantaris palmaris et disseminata (also known as porokeratosis plantaris) is unique among the subtypes of porokeratosis in that its annular, red-pink, papular rash with scaling and a keratotic border tends to start distally, involving the palms and soles, and progresses proximally to the trunk with smaller lesions.^1,7 This centripetal progression can take years, as was seen in our patient.¹ The disease is uncommon, with a dearth of published reports on PPPD.² However, case reports have shown that PPPD is strongly linked to family history and may have an autosomal-dominant inheritance pattern. Penetrance is greater in men than in women, as PPPD is twice as common in men.⁸ Most cases of PPPD have been diagnosed in patients in their 20s and 30s, but Hartman et al9 reported a case wherein a patient was diagnosed with PPPD after 65 years of age, similar to our patient.

Although the lesions in DSAP can appear similar to those in PPPD, DSAP is more common among the family of porokeratotic conditions, affecting women twice as often as men, with a sporadic pattern of inheritance.² These same features are present in some other types of porokeratosis but not PPPD. Furthermore, DSAP progresses proximally to distally but often with truncal sparing.²

Akin to PPPD, pityriasis rubra pilaris (PRP) often presents with palmoplantar keratoderma.¹⁰ There are at least 6 types of PRP with varying degrees of similarity to PPPD. However, in many cases PRP is associated with a background of diffuse erythema on the body with islands of spared skin. In addition, cases of PRP have been linked to extracutaneous findings such as ectropion and joint pain.¹¹

Darier disease, especially the acrokeratosis verruciformis of Hopf variant, is more common in men and involves younger populations, as in PPPD.¹¹ However, the crusted lesions seen in Darier disease frequently involve the skin folds. These intertriginous lesions may coalesce, mimicking warts in appearance, and are at risk for secondary infection. Nail findings in Darier disease also are distinct and include longitudinal white or red stripes running along the nail bed, in addition to V-shaped nicks at the nail tips.

Psoriasis can occur anywhere on the body and is associated with silver scaling atop a salmon-colored dermatitis.¹² It results from aberrant proliferation of keratinocytes. Some distinguishing features of psoriasis include a disease course that waxes and wanes as well as pitting of the nails.

Although PPPD typically affects young adults, we presented a case of PPPD in an older man. Porokeratosis plantaris palmaris et disseminata in older adults may represent a delayed diagnosis, imply a broader range for the age of onset, or suggest its manifestation secondary to radiation treatment or another phenomenon. For example, our patient received 35 radiotherapy cycles for tongue cancer more than 5 years prior to the onset of PPPD.

The Diagnosis: Porokeratosis Plantaris Palmaris et Disseminata

A 3-mm punch biopsy of the right upper arm showed incipient cornoid lamellae formation, pigment incontinence, and sparse dermal lymphocytic inflammation (Figure), suggestive of porokeratosis plantaris palmaris et disseminata (PPPD). The dermatopathologist recommended a second biopsy to confirm the diagnosis and to confirm that the lesions on the palms and soles also were suggestive of porokeratosis. A second 4-mm punch biopsy of the left palm was consistent with PPPD.

The risks of PPPD as a precancerous entity along with the benefits and side effects of the various management options were discussed with our patient. We recommended that he start low-dose isotretinoin (20 mg/d) due to the large body surface area affected, making focal and field treatments likely insufficient. However, our patient opted not to treat and did not return for follow-up.

Subtypes of porokeratosis, including disseminated superficial actinic porokeratosis (DSAP) and PPPD, are conditions that disrupt the normal maturation of keratin and present clinically with symmetric, crusted, annular papules.¹ The signature but nonspecific histopathologic feature shared among the subtypes is the presence of a cornoid lamellae.² Several triggers of porokeratosis have been proposed, including trauma and exposure to UV and ionizing radiation.^2,3 The clinical variants of porokeratosis are important conditions to diagnose correctly because they portend a risk for Bowen disease and invasive squamous cell carcinoma and may indicate the presence of an underlying hematologic and/or solid organ malignancy.⁴ Management of porokeratosis is difficult, as treatments have shown limited efficacy and variable recurrence rates. Treatment options include focal, field, and systemic options, such as 5-fluorouracil, topical compound of cholesterol and lovastatin, isotretinoin, and acitretin.^1,2

Porokeratoses may arise from gene mutations in the mevalonate pathway,⁵ which is essential for the production of cholesterol.⁶ Topical cholesterol alone has not been shown to improve porokeratosis, but the combination topical therapy of cholesterol and lovastatin is promising. It is theorized to deliver benefit by both providing the essential end product of the pathway and simultaneously reducing the number of potentially toxic intermediates.⁶

Porokeratosis plantaris palmaris et disseminata (also known as porokeratosis plantaris) is unique among the subtypes of porokeratosis in that its annular, red-pink, papular rash with scaling and a keratotic border tends to start distally, involving the palms and soles, and progresses proximally to the trunk with smaller lesions.^1,7 This centripetal progression can take years, as was seen in our patient.¹ The disease is uncommon, with a dearth of published reports on PPPD.² However, case reports have shown that PPPD is strongly linked to family history and may have an autosomal-dominant inheritance pattern. Penetrance is greater in men than in women, as PPPD is twice as common in men.⁸ Most cases of PPPD have been diagnosed in patients in their 20s and 30s, but Hartman et al9 reported a case wherein a patient was diagnosed with PPPD after 65 years of age, similar to our patient.

Although the lesions in DSAP can appear similar to those in PPPD, DSAP is more common among the family of porokeratotic conditions, affecting women twice as often as men, with a sporadic pattern of inheritance.² These same features are present in some other types of porokeratosis but not PPPD. Furthermore, DSAP progresses proximally to distally but often with truncal sparing.²

Akin to PPPD, pityriasis rubra pilaris (PRP) often presents with palmoplantar keratoderma.¹⁰ There are at least 6 types of PRP with varying degrees of similarity to PPPD. However, in many cases PRP is associated with a background of diffuse erythema on the body with islands of spared skin. In addition, cases of PRP have been linked to extracutaneous findings such as ectropion and joint pain.¹¹

Darier disease, especially the acrokeratosis verruciformis of Hopf variant, is more common in men and involves younger populations, as in PPPD.¹¹ However, the crusted lesions seen in Darier disease frequently involve the skin folds. These intertriginous lesions may coalesce, mimicking warts in appearance, and are at risk for secondary infection. Nail findings in Darier disease also are distinct and include longitudinal white or red stripes running along the nail bed, in addition to V-shaped nicks at the nail tips.

Psoriasis can occur anywhere on the body and is associated with silver scaling atop a salmon-colored dermatitis.¹² It results from aberrant proliferation of keratinocytes. Some distinguishing features of psoriasis include a disease course that waxes and wanes as well as pitting of the nails.

Although PPPD typically affects young adults, we presented a case of PPPD in an older man. Porokeratosis plantaris palmaris et disseminata in older adults may represent a delayed diagnosis, imply a broader range for the age of onset, or suggest its manifestation secondary to radiation treatment or another phenomenon. For example, our patient received 35 radiotherapy cycles for tongue cancer more than 5 years prior to the onset of PPPD.

The Diagnosis: Porokeratosis Plantaris Palmaris et Disseminata

A 3-mm punch biopsy of the right upper arm showed incipient cornoid lamellae formation, pigment incontinence, and sparse dermal lymphocytic inflammation (Figure), suggestive of porokeratosis plantaris palmaris et disseminata (PPPD). The dermatopathologist recommended a second biopsy to confirm the diagnosis and to confirm that the lesions on the palms and soles also were suggestive of porokeratosis. A second 4-mm punch biopsy of the left palm was consistent with PPPD.

The risks of PPPD as a precancerous entity along with the benefits and side effects of the various management options were discussed with our patient. We recommended that he start low-dose isotretinoin (20 mg/d) due to the large body surface area affected, making focal and field treatments likely insufficient. However, our patient opted not to treat and did not return for follow-up.

Subtypes of porokeratosis, including disseminated superficial actinic porokeratosis (DSAP) and PPPD, are conditions that disrupt the normal maturation of keratin and present clinically with symmetric, crusted, annular papules.¹ The signature but nonspecific histopathologic feature shared among the subtypes is the presence of a cornoid lamellae.² Several triggers of porokeratosis have been proposed, including trauma and exposure to UV and ionizing radiation.^2,3 The clinical variants of porokeratosis are important conditions to diagnose correctly because they portend a risk for Bowen disease and invasive squamous cell carcinoma and may indicate the presence of an underlying hematologic and/or solid organ malignancy.⁴ Management of porokeratosis is difficult, as treatments have shown limited efficacy and variable recurrence rates. Treatment options include focal, field, and systemic options, such as 5-fluorouracil, topical compound of cholesterol and lovastatin, isotretinoin, and acitretin.^1,2

Porokeratoses may arise from gene mutations in the mevalonate pathway,⁵ which is essential for the production of cholesterol.⁶ Topical cholesterol alone has not been shown to improve porokeratosis, but the combination topical therapy of cholesterol and lovastatin is promising. It is theorized to deliver benefit by both providing the essential end product of the pathway and simultaneously reducing the number of potentially toxic intermediates.⁶

Porokeratosis plantaris palmaris et disseminata (also known as porokeratosis plantaris) is unique among the subtypes of porokeratosis in that its annular, red-pink, papular rash with scaling and a keratotic border tends to start distally, involving the palms and soles, and progresses proximally to the trunk with smaller lesions.^1,7 This centripetal progression can take years, as was seen in our patient.¹ The disease is uncommon, with a dearth of published reports on PPPD.² However, case reports have shown that PPPD is strongly linked to family history and may have an autosomal-dominant inheritance pattern. Penetrance is greater in men than in women, as PPPD is twice as common in men.⁸ Most cases of PPPD have been diagnosed in patients in their 20s and 30s, but Hartman et al9 reported a case wherein a patient was diagnosed with PPPD after 65 years of age, similar to our patient.

Although the lesions in DSAP can appear similar to those in PPPD, DSAP is more common among the family of porokeratotic conditions, affecting women twice as often as men, with a sporadic pattern of inheritance.² These same features are present in some other types of porokeratosis but not PPPD. Furthermore, DSAP progresses proximally to distally but often with truncal sparing.²

Akin to PPPD, pityriasis rubra pilaris (PRP) often presents with palmoplantar keratoderma.¹⁰ There are at least 6 types of PRP with varying degrees of similarity to PPPD. However, in many cases PRP is associated with a background of diffuse erythema on the body with islands of spared skin. In addition, cases of PRP have been linked to extracutaneous findings such as ectropion and joint pain.¹¹

Darier disease, especially the acrokeratosis verruciformis of Hopf variant, is more common in men and involves younger populations, as in PPPD.¹¹ However, the crusted lesions seen in Darier disease frequently involve the skin folds. These intertriginous lesions may coalesce, mimicking warts in appearance, and are at risk for secondary infection. Nail findings in Darier disease also are distinct and include longitudinal white or red stripes running along the nail bed, in addition to V-shaped nicks at the nail tips.

Psoriasis can occur anywhere on the body and is associated with silver scaling atop a salmon-colored dermatitis.¹² It results from aberrant proliferation of keratinocytes. Some distinguishing features of psoriasis include a disease course that waxes and wanes as well as pitting of the nails.

Although PPPD typically affects young adults, we presented a case of PPPD in an older man. Porokeratosis plantaris palmaris et disseminata in older adults may represent a delayed diagnosis, imply a broader range for the age of onset, or suggest its manifestation secondary to radiation treatment or another phenomenon. For example, our patient received 35 radiotherapy cycles for tongue cancer more than 5 years prior to the onset of PPPD.

To the Editor:

Subcutaneous panniculitic T-cell lymphoma (SPTCL) is a rare cutaneous T-cell lymphoma that was first described in 1991¹ and comprises less than 1% of all non-Hodgkin lymphomas (NHLs). It most commonly occurs in young adults, with a median patient age of 36 years and a slight female predominance.² Patients typically present with skin nodules or deep-seated plaques involving the legs, arms, and/or trunk. Presentation on the face is less common.^2,3 Paraneoplastic edema has been reported in several cases of SPTCL with facial and periorbital swelling.^4-9

Diagnosis of SPTCL is achieved via analysis of a deep tissue skin biopsy and close clinicopathologic correlation. Histopathology demonstrates lobular panniculitis with an atypical lymphoid infiltrate in the subcutaneous tissue with predominantly CD8⁺ T cells without overlying epidermotropism or interface dermatitis.³ The degree of cellular atypia, fat necrosis, karyorrhexis, cytophagia, and lack of angioinvasion can help to distinguish SPTCL from other panniculitides.^2,3

The prognosis of SPTCL is good, with a 5-year survival rate of 82%, and many patients are able to achieve remission.² However, SPTCL can progress to a fatal hemophagocytic syndrome, which has been reported in 17% of cases, making early diagnosis and treatment of this malignancy imperative.^1,2 Treatment varies depending on the progression and extent of disease and can include the use of steroids, multidrug chemotherapy regimens, radiotherapy, and stem cell transplant in refractory cases.^2-4,10,11

Subcutaneous panniculitic T-cell lymphoma with edema has been reported in a 2-year-old child.¹² We present a case of SPTCL in an adult patient with known stage IV chronic lymphocytic leukemia (CLL) who also had full-body edema.

A 60-year-old woman with a 7-year history of stage IV CLL presented with anasarca of 3 months’ duration. At the time of presentation to dermatology, physical examination revealed erythematous tender nodules on the arms and legs. She had no other medical conditions and was undergoing treatment with ibrutinib for the CLL. The patient reported profound fatigue but no fever, chills, night sweats, cough, or dyspnea. The swelling had begun initially in the legs and progressively worsened to involve the arms, face, and body. She was hospitalized and treated with intravenous steroids and antihistamines, which led to minor improvement in the swelling. The patient’s preliminary diagnosis of erythema nodosum was thought to be related to the CLL or ibrutinib; therefore, treatment subsequently was discontinued and she was discharged from the hospital.

The swelling continued to worsen over the following 3 months, and the patient gained approximately 25 pounds. She presented to our office again with severe periorbital, facial, and lip edema as well as diffuse edema of the torso, arms, and legs (Figure 1). Erythematous tender subcutaneous nodules were noted on the right proximal thigh, left lateral calf, and forearms. She was again hospitalized, and extensive evaluation was performed to exclude other causes of anasarca, including a complete blood cell count; comprehensive metabolic profile; hepatitis panels; HIV test; C3 and C4, complement CH50, C1 esterase inhibitor, IgE, and angiotensin-converting enzyme levels; urine protein to creatinine ratio; computed tomography of the chest, abdomen, and pelvis; and allergy evaluation. The analyses failed to reveal the cause of the anasarca.

During hospitalization, the patient underwent a lymph node biopsy, bone marrow biopsy, and a 6-mm punch biopsy of the right thigh nodule. The lymph node and bone marrow biopsy results were consistent with the known diagnosis of CLL, and the patient was started on intravenous chemotherapy with bendamustine. The skin biopsy demonstrated a predominant T-cell infiltrate consistent with a lobular panniculitis with variable amounts of adipocytes rimmed by lymphocytes, nuclear debris, and karyorrhexis (Figure 2). CD3⁺, CD8⁺, and CD4⁻ T cells were positive for T-cell receptor (TCR) βF1 and negative for TCR-γ with strong expression of cytotoxic markers including granzyme B, perforin, and T-cell intracytoplasmic antigen 1. Rare CD56⁺ cells also were noted. The biopsy did not demonstrate any notable interface dermatitis, epidermotropism, or angioinvasion. T-cell receptor gene rearrangement studies did not show clonality for γ- or β-chain probes. Subcutaneous panniculitic T-cell lymphoma was diagnosed, making this case unique with the presentation of anasarca. This case also is noteworthy due to the rare diagnosis of the secondary malignancy of SPTCL in a patient with known CLL. The patient opted to pursue hospice and comfort measures due to the effects of persistent pancytopenia and the progression of CLL. She died 2 months later.

Clinical courses of SPTCL vary based on the TCR phenotype and immunophenotypic characteristics of the tumor cells. The TCR-αβ phenotype, as described in this case, typically is CD4⁻, CD8⁺, and CD56^– and leads to a more indolent disease course. Lymphomas with the TCR-γδ phenotype typically are CD4⁻, CD8⁻, and CD56⁺; they often are associated with hemophagocytic syndrome and thus a worse prognosis. In 2009, the World Health Organization–European Organization for Research and Treatment of Cancer classification of primary cutaneous lymphomas restricted the category of SPTCL to the TCR-αβ phenotype due to the stark differences between the 2 types. The TCR-γδ phenotype was given its own diagnostic category—primary cutaneous γδ T-cell lymphoma.³

Patients with SPTCL commonly present with nodular skin lesions or deep-seated plaques on the legs, arms, and/or trunk; presentation on the face is rare.^2,3 Fever, chills, night sweats, and/or weight loss were present in approximately 50% of recorded cases. Underlying autoimmune disease was present in 12 of 63 (19%) patients in a 2008 study.² Facial and periorbital swelling with SPTCL has been reported.^4-9 The presentation of anasarca, as seen in our adult patient, has been reported in a 2-year-old child.¹² Anasarca as a presenting symptom of NHL is a rare phenomenon proposed to be induced by malignant cells secreting a cytokine that causes a vascular leak syndrome.¹³ Specifically, tumor necrosis factor α was found to be elevated in at least 2 patients with NHL presenting with anasarca in a prior study. Tumor necrosis factor α is known to cause increased capillary permeability, vascular leakage, and development of edema.¹³ In retrospect, obtaining cytokine levels in our patient would have been useful to support or refute tumor necrosis factor α as a possible cause of anasarca in the setting of NHL. This case continues to highlight that a diagnosis of SPTCL and analysis of a skin biopsy should be considered in cases of sudden unremitting facial and/or body swelling that cannot be explained by other more common causes.

Subcutaneous panniculitic T-cell lymphoma can be diagnosed and distinguished from other panniculitides via analysis of a deep tissue skin biopsy. Multiple biopsies may be required to ensure an adequate sample is obtained.⁴ Histopathology displays an atypical lymphoid infiltrate with a predominant presence of T cells. Neoplastic cells show CD3⁺, CD8⁺, and CD4⁻ T cells, which strongly express cytotoxic proteins such as granzyme B, T-cell intracellular antigen 1, and perforin.³ The degree of cellular atypia, fat necrosis, karyorrhexis, and cytophagia, as well as the lack of angioinvasion, interface dermatitis, and epidermotropism help to distinguish SPTCL from other panniculitides.^2,3 According to a previous study, clonal TCR gene rearrangement was identified in 50% to 80% of cases, but the absence of this clonal rearrangement does not exclude the diagnosis.¹⁴

This case also highlights the occurrence of secondary malignancies in patients with CLL, an NHL that is classified as a low-grade lymphoproliferative malignancy with clonal expansion of B cells.¹⁵ Secondary CTCLs in patients with CLL are rare, but they have been previously described. In 2017, Chang et al¹⁶ identified 12 patients with CLL who subsequently developed CTCL between 1992 and 2008. Of the 12 patients, 7 developed mycosis fungoides, 3 had CTCL not otherwise specified, 1 had mature T-cell lymphoma not otherwise specified, and 1 had primary cutaneous CD30⁺ T-cell lymphoma.¹⁶ The proliferation of 2 separate lymphocytic lineages is rare, but this study demonstrated an increased risk for CTCL to develop in patients with CLL. One possible explanation is that malignant cells come from a common stem cell progenitor or from genetic events. They occur secondary to carcinogens, viruses, or cytokines from T-cell or B-cell clones; they evolve due to treatment of the preexisting lymphoproliferative disease; or they occur simply by coincidence. The behavior of the CTCL may be more aggressive in patients with CLL due to immunosuppression, which may have contributed to the extreme presentation in our patient.¹⁶ Subcutaneous panniculitic T-cell lymphoma also has been reported in a patient with CLL that was thought to be associated with prior rituximab treatment.¹⁷

Treatment of SPTCL depends on the severity and course of the disease. In patients with more indolent disease, systemic steroids have been the most frequently used initial treatment.^2,3,10 However, the disease often will progress after steroid tapering and require further intervention. Localized lesions may be treated with radiation alone or in combination with other systemic therapies.^3,10 In refractory, aggressive, or relapsing cases, polychemotherapeutic regimens have proven to produce long-term remission in 30% of patients, with an overall response rate of 50%.¹⁰ These regimens most commonly have included cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like treatment (EPOCH regimen [etoposide, prednisone, oncovin, cyclophosphamide, and doxorubicin hydrochloride]).^3,10 A stem cell transplant can be considered in patients with recurrent and refractory disease, and it also has been shown to induce remission.^4,17 In patients with a good response to therapy, the disease often can be controlled for long periods of time, with an estimated 5-year survival rate of 80%.¹⁵

This case highlights the diagnostic challenges and variable presentations of SPTCL. Dermatologists, oncologists, and dermatopathologists should be aware of this condition and consider it in the differential diagnosis of a patient with a hematologic malignancy and unremitting facial and/or body swelling without any other cause. The possibility of a secondary hematologic cancer in a patient with CLL also must be taken into consideration. Early diagnosis and treatment can minimize morbidity and induce remission in most patients.

To the Editor:

Subcutaneous panniculitic T-cell lymphoma (SPTCL) is a rare cutaneous T-cell lymphoma that was first described in 1991¹ and comprises less than 1% of all non-Hodgkin lymphomas (NHLs). It most commonly occurs in young adults, with a median patient age of 36 years and a slight female predominance.² Patients typically present with skin nodules or deep-seated plaques involving the legs, arms, and/or trunk. Presentation on the face is less common.^2,3 Paraneoplastic edema has been reported in several cases of SPTCL with facial and periorbital swelling.^4-9

Diagnosis of SPTCL is achieved via analysis of a deep tissue skin biopsy and close clinicopathologic correlation. Histopathology demonstrates lobular panniculitis with an atypical lymphoid infiltrate in the subcutaneous tissue with predominantly CD8⁺ T cells without overlying epidermotropism or interface dermatitis.³ The degree of cellular atypia, fat necrosis, karyorrhexis, cytophagia, and lack of angioinvasion can help to distinguish SPTCL from other panniculitides.^2,3

The prognosis of SPTCL is good, with a 5-year survival rate of 82%, and many patients are able to achieve remission.² However, SPTCL can progress to a fatal hemophagocytic syndrome, which has been reported in 17% of cases, making early diagnosis and treatment of this malignancy imperative.^1,2 Treatment varies depending on the progression and extent of disease and can include the use of steroids, multidrug chemotherapy regimens, radiotherapy, and stem cell transplant in refractory cases.^2-4,10,11

Subcutaneous panniculitic T-cell lymphoma with edema has been reported in a 2-year-old child.¹² We present a case of SPTCL in an adult patient with known stage IV chronic lymphocytic leukemia (CLL) who also had full-body edema.

A 60-year-old woman with a 7-year history of stage IV CLL presented with anasarca of 3 months’ duration. At the time of presentation to dermatology, physical examination revealed erythematous tender nodules on the arms and legs. She had no other medical conditions and was undergoing treatment with ibrutinib for the CLL. The patient reported profound fatigue but no fever, chills, night sweats, cough, or dyspnea. The swelling had begun initially in the legs and progressively worsened to involve the arms, face, and body. She was hospitalized and treated with intravenous steroids and antihistamines, which led to minor improvement in the swelling. The patient’s preliminary diagnosis of erythema nodosum was thought to be related to the CLL or ibrutinib; therefore, treatment subsequently was discontinued and she was discharged from the hospital.

The swelling continued to worsen over the following 3 months, and the patient gained approximately 25 pounds. She presented to our office again with severe periorbital, facial, and lip edema as well as diffuse edema of the torso, arms, and legs (Figure 1). Erythematous tender subcutaneous nodules were noted on the right proximal thigh, left lateral calf, and forearms. She was again hospitalized, and extensive evaluation was performed to exclude other causes of anasarca, including a complete blood cell count; comprehensive metabolic profile; hepatitis panels; HIV test; C3 and C4, complement CH50, C1 esterase inhibitor, IgE, and angiotensin-converting enzyme levels; urine protein to creatinine ratio; computed tomography of the chest, abdomen, and pelvis; and allergy evaluation. The analyses failed to reveal the cause of the anasarca.

During hospitalization, the patient underwent a lymph node biopsy, bone marrow biopsy, and a 6-mm punch biopsy of the right thigh nodule. The lymph node and bone marrow biopsy results were consistent with the known diagnosis of CLL, and the patient was started on intravenous chemotherapy with bendamustine. The skin biopsy demonstrated a predominant T-cell infiltrate consistent with a lobular panniculitis with variable amounts of adipocytes rimmed by lymphocytes, nuclear debris, and karyorrhexis (Figure 2). CD3⁺, CD8⁺, and CD4⁻ T cells were positive for T-cell receptor (TCR) βF1 and negative for TCR-γ with strong expression of cytotoxic markers including granzyme B, perforin, and T-cell intracytoplasmic antigen 1. Rare CD56⁺ cells also were noted. The biopsy did not demonstrate any notable interface dermatitis, epidermotropism, or angioinvasion. T-cell receptor gene rearrangement studies did not show clonality for γ- or β-chain probes. Subcutaneous panniculitic T-cell lymphoma was diagnosed, making this case unique with the presentation of anasarca. This case also is noteworthy due to the rare diagnosis of the secondary malignancy of SPTCL in a patient with known CLL. The patient opted to pursue hospice and comfort measures due to the effects of persistent pancytopenia and the progression of CLL. She died 2 months later.

Clinical courses of SPTCL vary based on the TCR phenotype and immunophenotypic characteristics of the tumor cells. The TCR-αβ phenotype, as described in this case, typically is CD4⁻, CD8⁺, and CD56^– and leads to a more indolent disease course. Lymphomas with the TCR-γδ phenotype typically are CD4⁻, CD8⁻, and CD56⁺; they often are associated with hemophagocytic syndrome and thus a worse prognosis. In 2009, the World Health Organization–European Organization for Research and Treatment of Cancer classification of primary cutaneous lymphomas restricted the category of SPTCL to the TCR-αβ phenotype due to the stark differences between the 2 types. The TCR-γδ phenotype was given its own diagnostic category—primary cutaneous γδ T-cell lymphoma.³

Patients with SPTCL commonly present with nodular skin lesions or deep-seated plaques on the legs, arms, and/or trunk; presentation on the face is rare.^2,3 Fever, chills, night sweats, and/or weight loss were present in approximately 50% of recorded cases. Underlying autoimmune disease was present in 12 of 63 (19%) patients in a 2008 study.² Facial and periorbital swelling with SPTCL has been reported.^4-9 The presentation of anasarca, as seen in our adult patient, has been reported in a 2-year-old child.¹² Anasarca as a presenting symptom of NHL is a rare phenomenon proposed to be induced by malignant cells secreting a cytokine that causes a vascular leak syndrome.¹³ Specifically, tumor necrosis factor α was found to be elevated in at least 2 patients with NHL presenting with anasarca in a prior study. Tumor necrosis factor α is known to cause increased capillary permeability, vascular leakage, and development of edema.¹³ In retrospect, obtaining cytokine levels in our patient would have been useful to support or refute tumor necrosis factor α as a possible cause of anasarca in the setting of NHL. This case continues to highlight that a diagnosis of SPTCL and analysis of a skin biopsy should be considered in cases of sudden unremitting facial and/or body swelling that cannot be explained by other more common causes.

Subcutaneous panniculitic T-cell lymphoma can be diagnosed and distinguished from other panniculitides via analysis of a deep tissue skin biopsy. Multiple biopsies may be required to ensure an adequate sample is obtained.⁴ Histopathology displays an atypical lymphoid infiltrate with a predominant presence of T cells. Neoplastic cells show CD3⁺, CD8⁺, and CD4⁻ T cells, which strongly express cytotoxic proteins such as granzyme B, T-cell intracellular antigen 1, and perforin.³ The degree of cellular atypia, fat necrosis, karyorrhexis, and cytophagia, as well as the lack of angioinvasion, interface dermatitis, and epidermotropism help to distinguish SPTCL from other panniculitides.^2,3 According to a previous study, clonal TCR gene rearrangement was identified in 50% to 80% of cases, but the absence of this clonal rearrangement does not exclude the diagnosis.¹⁴

This case also highlights the occurrence of secondary malignancies in patients with CLL, an NHL that is classified as a low-grade lymphoproliferative malignancy with clonal expansion of B cells.¹⁵ Secondary CTCLs in patients with CLL are rare, but they have been previously described. In 2017, Chang et al¹⁶ identified 12 patients with CLL who subsequently developed CTCL between 1992 and 2008. Of the 12 patients, 7 developed mycosis fungoides, 3 had CTCL not otherwise specified, 1 had mature T-cell lymphoma not otherwise specified, and 1 had primary cutaneous CD30⁺ T-cell lymphoma.¹⁶ The proliferation of 2 separate lymphocytic lineages is rare, but this study demonstrated an increased risk for CTCL to develop in patients with CLL. One possible explanation is that malignant cells come from a common stem cell progenitor or from genetic events. They occur secondary to carcinogens, viruses, or cytokines from T-cell or B-cell clones; they evolve due to treatment of the preexisting lymphoproliferative disease; or they occur simply by coincidence. The behavior of the CTCL may be more aggressive in patients with CLL due to immunosuppression, which may have contributed to the extreme presentation in our patient.¹⁶ Subcutaneous panniculitic T-cell lymphoma also has been reported in a patient with CLL that was thought to be associated with prior rituximab treatment.¹⁷

Treatment of SPTCL depends on the severity and course of the disease. In patients with more indolent disease, systemic steroids have been the most frequently used initial treatment.^2,3,10 However, the disease often will progress after steroid tapering and require further intervention. Localized lesions may be treated with radiation alone or in combination with other systemic therapies.^3,10 In refractory, aggressive, or relapsing cases, polychemotherapeutic regimens have proven to produce long-term remission in 30% of patients, with an overall response rate of 50%.¹⁰ These regimens most commonly have included cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like treatment (EPOCH regimen [etoposide, prednisone, oncovin, cyclophosphamide, and doxorubicin hydrochloride]).^3,10 A stem cell transplant can be considered in patients with recurrent and refractory disease, and it also has been shown to induce remission.^4,17 In patients with a good response to therapy, the disease often can be controlled for long periods of time, with an estimated 5-year survival rate of 80%.¹⁵

This case highlights the diagnostic challenges and variable presentations of SPTCL. Dermatologists, oncologists, and dermatopathologists should be aware of this condition and consider it in the differential diagnosis of a patient with a hematologic malignancy and unremitting facial and/or body swelling without any other cause. The possibility of a secondary hematologic cancer in a patient with CLL also must be taken into consideration. Early diagnosis and treatment can minimize morbidity and induce remission in most patients.

To the Editor:

Subcutaneous panniculitic T-cell lymphoma (SPTCL) is a rare cutaneous T-cell lymphoma that was first described in 1991¹ and comprises less than 1% of all non-Hodgkin lymphomas (NHLs). It most commonly occurs in young adults, with a median patient age of 36 years and a slight female predominance.² Patients typically present with skin nodules or deep-seated plaques involving the legs, arms, and/or trunk. Presentation on the face is less common.^2,3 Paraneoplastic edema has been reported in several cases of SPTCL with facial and periorbital swelling.^4-9

Diagnosis of SPTCL is achieved via analysis of a deep tissue skin biopsy and close clinicopathologic correlation. Histopathology demonstrates lobular panniculitis with an atypical lymphoid infiltrate in the subcutaneous tissue with predominantly CD8⁺ T cells without overlying epidermotropism or interface dermatitis.³ The degree of cellular atypia, fat necrosis, karyorrhexis, cytophagia, and lack of angioinvasion can help to distinguish SPTCL from other panniculitides.^2,3

The prognosis of SPTCL is good, with a 5-year survival rate of 82%, and many patients are able to achieve remission.² However, SPTCL can progress to a fatal hemophagocytic syndrome, which has been reported in 17% of cases, making early diagnosis and treatment of this malignancy imperative.^1,2 Treatment varies depending on the progression and extent of disease and can include the use of steroids, multidrug chemotherapy regimens, radiotherapy, and stem cell transplant in refractory cases.^2-4,10,11

Subcutaneous panniculitic T-cell lymphoma with edema has been reported in a 2-year-old child.¹² We present a case of SPTCL in an adult patient with known stage IV chronic lymphocytic leukemia (CLL) who also had full-body edema.

A 60-year-old woman with a 7-year history of stage IV CLL presented with anasarca of 3 months’ duration. At the time of presentation to dermatology, physical examination revealed erythematous tender nodules on the arms and legs. She had no other medical conditions and was undergoing treatment with ibrutinib for the CLL. The patient reported profound fatigue but no fever, chills, night sweats, cough, or dyspnea. The swelling had begun initially in the legs and progressively worsened to involve the arms, face, and body. She was hospitalized and treated with intravenous steroids and antihistamines, which led to minor improvement in the swelling. The patient’s preliminary diagnosis of erythema nodosum was thought to be related to the CLL or ibrutinib; therefore, treatment subsequently was discontinued and she was discharged from the hospital.

The swelling continued to worsen over the following 3 months, and the patient gained approximately 25 pounds. She presented to our office again with severe periorbital, facial, and lip edema as well as diffuse edema of the torso, arms, and legs (Figure 1). Erythematous tender subcutaneous nodules were noted on the right proximal thigh, left lateral calf, and forearms. She was again hospitalized, and extensive evaluation was performed to exclude other causes of anasarca, including a complete blood cell count; comprehensive metabolic profile; hepatitis panels; HIV test; C3 and C4, complement CH50, C1 esterase inhibitor, IgE, and angiotensin-converting enzyme levels; urine protein to creatinine ratio; computed tomography of the chest, abdomen, and pelvis; and allergy evaluation. The analyses failed to reveal the cause of the anasarca.

During hospitalization, the patient underwent a lymph node biopsy, bone marrow biopsy, and a 6-mm punch biopsy of the right thigh nodule. The lymph node and bone marrow biopsy results were consistent with the known diagnosis of CLL, and the patient was started on intravenous chemotherapy with bendamustine. The skin biopsy demonstrated a predominant T-cell infiltrate consistent with a lobular panniculitis with variable amounts of adipocytes rimmed by lymphocytes, nuclear debris, and karyorrhexis (Figure 2). CD3⁺, CD8⁺, and CD4⁻ T cells were positive for T-cell receptor (TCR) βF1 and negative for TCR-γ with strong expression of cytotoxic markers including granzyme B, perforin, and T-cell intracytoplasmic antigen 1. Rare CD56⁺ cells also were noted. The biopsy did not demonstrate any notable interface dermatitis, epidermotropism, or angioinvasion. T-cell receptor gene rearrangement studies did not show clonality for γ- or β-chain probes. Subcutaneous panniculitic T-cell lymphoma was diagnosed, making this case unique with the presentation of anasarca. This case also is noteworthy due to the rare diagnosis of the secondary malignancy of SPTCL in a patient with known CLL. The patient opted to pursue hospice and comfort measures due to the effects of persistent pancytopenia and the progression of CLL. She died 2 months later.

Clinical courses of SPTCL vary based on the TCR phenotype and immunophenotypic characteristics of the tumor cells. The TCR-αβ phenotype, as described in this case, typically is CD4⁻, CD8⁺, and CD56^– and leads to a more indolent disease course. Lymphomas with the TCR-γδ phenotype typically are CD4⁻, CD8⁻, and CD56⁺; they often are associated with hemophagocytic syndrome and thus a worse prognosis. In 2009, the World Health Organization–European Organization for Research and Treatment of Cancer classification of primary cutaneous lymphomas restricted the category of SPTCL to the TCR-αβ phenotype due to the stark differences between the 2 types. The TCR-γδ phenotype was given its own diagnostic category—primary cutaneous γδ T-cell lymphoma.³

Patients with SPTCL commonly present with nodular skin lesions or deep-seated plaques on the legs, arms, and/or trunk; presentation on the face is rare.^2,3 Fever, chills, night sweats, and/or weight loss were present in approximately 50% of recorded cases. Underlying autoimmune disease was present in 12 of 63 (19%) patients in a 2008 study.² Facial and periorbital swelling with SPTCL has been reported.^4-9 The presentation of anasarca, as seen in our adult patient, has been reported in a 2-year-old child.¹² Anasarca as a presenting symptom of NHL is a rare phenomenon proposed to be induced by malignant cells secreting a cytokine that causes a vascular leak syndrome.¹³ Specifically, tumor necrosis factor α was found to be elevated in at least 2 patients with NHL presenting with anasarca in a prior study. Tumor necrosis factor α is known to cause increased capillary permeability, vascular leakage, and development of edema.¹³ In retrospect, obtaining cytokine levels in our patient would have been useful to support or refute tumor necrosis factor α as a possible cause of anasarca in the setting of NHL. This case continues to highlight that a diagnosis of SPTCL and analysis of a skin biopsy should be considered in cases of sudden unremitting facial and/or body swelling that cannot be explained by other more common causes.

Subcutaneous panniculitic T-cell lymphoma can be diagnosed and distinguished from other panniculitides via analysis of a deep tissue skin biopsy. Multiple biopsies may be required to ensure an adequate sample is obtained.⁴ Histopathology displays an atypical lymphoid infiltrate with a predominant presence of T cells. Neoplastic cells show CD3⁺, CD8⁺, and CD4⁻ T cells, which strongly express cytotoxic proteins such as granzyme B, T-cell intracellular antigen 1, and perforin.³ The degree of cellular atypia, fat necrosis, karyorrhexis, and cytophagia, as well as the lack of angioinvasion, interface dermatitis, and epidermotropism help to distinguish SPTCL from other panniculitides.^2,3 According to a previous study, clonal TCR gene rearrangement was identified in 50% to 80% of cases, but the absence of this clonal rearrangement does not exclude the diagnosis.¹⁴

This case also highlights the occurrence of secondary malignancies in patients with CLL, an NHL that is classified as a low-grade lymphoproliferative malignancy with clonal expansion of B cells.¹⁵ Secondary CTCLs in patients with CLL are rare, but they have been previously described. In 2017, Chang et al¹⁶ identified 12 patients with CLL who subsequently developed CTCL between 1992 and 2008. Of the 12 patients, 7 developed mycosis fungoides, 3 had CTCL not otherwise specified, 1 had mature T-cell lymphoma not otherwise specified, and 1 had primary cutaneous CD30⁺ T-cell lymphoma.¹⁶ The proliferation of 2 separate lymphocytic lineages is rare, but this study demonstrated an increased risk for CTCL to develop in patients with CLL. One possible explanation is that malignant cells come from a common stem cell progenitor or from genetic events. They occur secondary to carcinogens, viruses, or cytokines from T-cell or B-cell clones; they evolve due to treatment of the preexisting lymphoproliferative disease; or they occur simply by coincidence. The behavior of the CTCL may be more aggressive in patients with CLL due to immunosuppression, which may have contributed to the extreme presentation in our patient.¹⁶ Subcutaneous panniculitic T-cell lymphoma also has been reported in a patient with CLL that was thought to be associated with prior rituximab treatment.¹⁷

Treatment of SPTCL depends on the severity and course of the disease. In patients with more indolent disease, systemic steroids have been the most frequently used initial treatment.^2,3,10 However, the disease often will progress after steroid tapering and require further intervention. Localized lesions may be treated with radiation alone or in combination with other systemic therapies.^3,10 In refractory, aggressive, or relapsing cases, polychemotherapeutic regimens have proven to produce long-term remission in 30% of patients, with an overall response rate of 50%.¹⁰ These regimens most commonly have included cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like treatment (EPOCH regimen [etoposide, prednisone, oncovin, cyclophosphamide, and doxorubicin hydrochloride]).^3,10 A stem cell transplant can be considered in patients with recurrent and refractory disease, and it also has been shown to induce remission.^4,17 In patients with a good response to therapy, the disease often can be controlled for long periods of time, with an estimated 5-year survival rate of 80%.¹⁵

This case highlights the diagnostic challenges and variable presentations of SPTCL. Dermatologists, oncologists, and dermatopathologists should be aware of this condition and consider it in the differential diagnosis of a patient with a hematologic malignancy and unremitting facial and/or body swelling without any other cause. The possibility of a secondary hematologic cancer in a patient with CLL also must be taken into consideration. Early diagnosis and treatment can minimize morbidity and induce remission in most patients.

The Diagnosis: Darier Disease

A clinical diagnosis of Darier disease was made from the skin findings of pruritic, malodorous, keratotic papules in a seborrheic distribution and pathognomonic nail dystrophy, along with a family history that demonstrated autosomal-dominant inheritance. The ulcerations were suspected to be caused by a superimposed herpes simplex virus (HSV) infection in the form of eczema herpeticum. The clinical diagnosis was later confirmed via punch biopsy. Pathology results demonstrated focal acantholytic dyskeratosis, which was consistent with Darier disease given the focal nature and lack of acanthosis. The patient’s father and sister also were confirmed to have Darier disease by an outside dermatologist.

Darier disease is a rare keratinizing autosomaldominant genodermatosis that occurs due to a mutation in the ATP2A2 gene, which encodes a sarco/endoplasmic reticulum calcium ATPase pump that decreases cell adhesion between keratinocytes, leading to epidermal acantholysis and dyskeratosis and ultimately a disrupted skin barrier.^1,2 Darier disease often presents in childhood and adolescence with papules in a seborrheic distribution on the central chest and back (Figure, A); the intertriginous folds also may be involved. Darier disease can manifest with palmoplantar pits (Figure, B), a cobblestonelike texture of the oral mucosa, acrokeratosis verruciformis of Hopf, and nail findings with alternating red and white longitudinal streaks in the nail bed resembling a candy cane along with characteristic V nicking deformities of the nails themselves (Figure, C). Chronic flares may occur throughout one’s lifetime, with patients experiencing more symptoms in the summer months due to heat, sweat, and UV light exposure, as well as infections that irritate the skin and worsen dyskeratosis. Studies have revealed an association between Darier disease and neuropsychiatric conditions, including major depressive disorder, schizophrenia, and bipolar disorder.^3,4

The skin barrier is compromised in patients with Darier disease, thereby making secondary infection more likely to occur. Polymerase chain reaction swabs of our patient’s purulent ulcerations were positive for HSV type 1, further strengthening a diagnosis of secondary eczema herpeticum, which occurs when patients have widespread HSV superinfecting pre-existing skin conditions such as atopic dermatitis, Darier disease, and Hailey-Hailey disease.^5-7 The lesions are characterized by a monomorphic eruption of umbilicated vesicles on an erythematous base. Lesions can progress to punched-out ulcers and erosions with hemorrhagic crusts that coalesce, forming scalloped borders, similar to our patient’s presentation.⁸

Hailey-Hailey disease, a genodermatosis that alters calcium signaling with an autosomal-dominant inheritance pattern, was unlikely in our patient due to the presence of nail abnormalities and palmar pits that are characteristic of Darier disease. From a purely histopathologic standpoint, Grover disease was considered with skin biopsy demonstrating acantholytic dyskeratosis but was not compatible with the clinical context. Furthermore, trials of antibiotics with group A Streptococcus and Staphylococcus aureus coverage failed in our patient, and she lacked systemic symptoms that would be supportive of a cellulitis diagnosis. The punched-out lesions suggested that an isolated exacerbation of atopic dermatitis was not sufficient to explain all of the clinical findings.

Eczema herpeticum must be considered in the differential diagnosis for patients with underlying Darier disease and widespread ulcerations. Our patient had more recent punched-out ulcerations in the intertriginous regions, with other areas showing later stages of confluent ulcers with scalloped borders. Delayed diagnosis and treatment of eczema herpeticum combined with severe Darier disease can lead to increased risk for hospitalization and rarely fatality.^8,9

Our patient was started on intravenous acyclovir until the lesions crusted and then was transitioned to a suppressive dose of oral valacyclovir given the widespread distribution. The Darier disease itself was managed with topical steroids and a zinc oxide barrier, serving as protectants to pathogens through microscopic breaks in the skin. Our patient also had a mild case of candidal intertrigo that was exacerbated by obesity and managed with topical ketoconazole. Gabapentin, hydromorphone, and acetaminophen were used for pain. She was discharged 10 days after admission with substantial improvement of both the HSV lesions and the irritation from her Darier disease. At follow-up visits 20 days later and again 6 months after discharge, she had been feeling well without any HSV flares.

The eczema herpeticum likely arose from our patient’s chronic skin barrier impairment attributed to Darier disease, leading to the cutaneous inoculation of HSV. Our patient and her family members had never been evaluated by a dermatologist until late in life during this hospitalization. Medication compliance with a suppressive dose of oral valacyclovir and topical steroids is vital to prevent flares of both eczema herpeticum and Darier disease, respectively. This case highlights the importance of dermatology consultation for complex cutaneous findings, as delayed diagnosis and treatment can lead to increased morbidity and mortality.

The Diagnosis: Darier Disease

A clinical diagnosis of Darier disease was made from the skin findings of pruritic, malodorous, keratotic papules in a seborrheic distribution and pathognomonic nail dystrophy, along with a family history that demonstrated autosomal-dominant inheritance. The ulcerations were suspected to be caused by a superimposed herpes simplex virus (HSV) infection in the form of eczema herpeticum. The clinical diagnosis was later confirmed via punch biopsy. Pathology results demonstrated focal acantholytic dyskeratosis, which was consistent with Darier disease given the focal nature and lack of acanthosis. The patient’s father and sister also were confirmed to have Darier disease by an outside dermatologist.

Darier disease is a rare keratinizing autosomaldominant genodermatosis that occurs due to a mutation in the ATP2A2 gene, which encodes a sarco/endoplasmic reticulum calcium ATPase pump that decreases cell adhesion between keratinocytes, leading to epidermal acantholysis and dyskeratosis and ultimately a disrupted skin barrier.^1,2 Darier disease often presents in childhood and adolescence with papules in a seborrheic distribution on the central chest and back (Figure, A); the intertriginous folds also may be involved. Darier disease can manifest with palmoplantar pits (Figure, B), a cobblestonelike texture of the oral mucosa, acrokeratosis verruciformis of Hopf, and nail findings with alternating red and white longitudinal streaks in the nail bed resembling a candy cane along with characteristic V nicking deformities of the nails themselves (Figure, C). Chronic flares may occur throughout one’s lifetime, with patients experiencing more symptoms in the summer months due to heat, sweat, and UV light exposure, as well as infections that irritate the skin and worsen dyskeratosis. Studies have revealed an association between Darier disease and neuropsychiatric conditions, including major depressive disorder, schizophrenia, and bipolar disorder.^3,4

The skin barrier is compromised in patients with Darier disease, thereby making secondary infection more likely to occur. Polymerase chain reaction swabs of our patient’s purulent ulcerations were positive for HSV type 1, further strengthening a diagnosis of secondary eczema herpeticum, which occurs when patients have widespread HSV superinfecting pre-existing skin conditions such as atopic dermatitis, Darier disease, and Hailey-Hailey disease.^5-7 The lesions are characterized by a monomorphic eruption of umbilicated vesicles on an erythematous base. Lesions can progress to punched-out ulcers and erosions with hemorrhagic crusts that coalesce, forming scalloped borders, similar to our patient’s presentation.⁸

Hailey-Hailey disease, a genodermatosis that alters calcium signaling with an autosomal-dominant inheritance pattern, was unlikely in our patient due to the presence of nail abnormalities and palmar pits that are characteristic of Darier disease. From a purely histopathologic standpoint, Grover disease was considered with skin biopsy demonstrating acantholytic dyskeratosis but was not compatible with the clinical context. Furthermore, trials of antibiotics with group A Streptococcus and Staphylococcus aureus coverage failed in our patient, and she lacked systemic symptoms that would be supportive of a cellulitis diagnosis. The punched-out lesions suggested that an isolated exacerbation of atopic dermatitis was not sufficient to explain all of the clinical findings.

Eczema herpeticum must be considered in the differential diagnosis for patients with underlying Darier disease and widespread ulcerations. Our patient had more recent punched-out ulcerations in the intertriginous regions, with other areas showing later stages of confluent ulcers with scalloped borders. Delayed diagnosis and treatment of eczema herpeticum combined with severe Darier disease can lead to increased risk for hospitalization and rarely fatality.^8,9

Our patient was started on intravenous acyclovir until the lesions crusted and then was transitioned to a suppressive dose of oral valacyclovir given the widespread distribution. The Darier disease itself was managed with topical steroids and a zinc oxide barrier, serving as protectants to pathogens through microscopic breaks in the skin. Our patient also had a mild case of candidal intertrigo that was exacerbated by obesity and managed with topical ketoconazole. Gabapentin, hydromorphone, and acetaminophen were used for pain. She was discharged 10 days after admission with substantial improvement of both the HSV lesions and the irritation from her Darier disease. At follow-up visits 20 days later and again 6 months after discharge, she had been feeling well without any HSV flares.

The eczema herpeticum likely arose from our patient’s chronic skin barrier impairment attributed to Darier disease, leading to the cutaneous inoculation of HSV. Our patient and her family members had never been evaluated by a dermatologist until late in life during this hospitalization. Medication compliance with a suppressive dose of oral valacyclovir and topical steroids is vital to prevent flares of both eczema herpeticum and Darier disease, respectively. This case highlights the importance of dermatology consultation for complex cutaneous findings, as delayed diagnosis and treatment can lead to increased morbidity and mortality.

The Diagnosis: Darier Disease

A clinical diagnosis of Darier disease was made from the skin findings of pruritic, malodorous, keratotic papules in a seborrheic distribution and pathognomonic nail dystrophy, along with a family history that demonstrated autosomal-dominant inheritance. The ulcerations were suspected to be caused by a superimposed herpes simplex virus (HSV) infection in the form of eczema herpeticum. The clinical diagnosis was later confirmed via punch biopsy. Pathology results demonstrated focal acantholytic dyskeratosis, which was consistent with Darier disease given the focal nature and lack of acanthosis. The patient’s father and sister also were confirmed to have Darier disease by an outside dermatologist.

Darier disease is a rare keratinizing autosomaldominant genodermatosis that occurs due to a mutation in the ATP2A2 gene, which encodes a sarco/endoplasmic reticulum calcium ATPase pump that decreases cell adhesion between keratinocytes, leading to epidermal acantholysis and dyskeratosis and ultimately a disrupted skin barrier.^1,2 Darier disease often presents in childhood and adolescence with papules in a seborrheic distribution on the central chest and back (Figure, A); the intertriginous folds also may be involved. Darier disease can manifest with palmoplantar pits (Figure, B), a cobblestonelike texture of the oral mucosa, acrokeratosis verruciformis of Hopf, and nail findings with alternating red and white longitudinal streaks in the nail bed resembling a candy cane along with characteristic V nicking deformities of the nails themselves (Figure, C). Chronic flares may occur throughout one’s lifetime, with patients experiencing more symptoms in the summer months due to heat, sweat, and UV light exposure, as well as infections that irritate the skin and worsen dyskeratosis. Studies have revealed an association between Darier disease and neuropsychiatric conditions, including major depressive disorder, schizophrenia, and bipolar disorder.^3,4

The skin barrier is compromised in patients with Darier disease, thereby making secondary infection more likely to occur. Polymerase chain reaction swabs of our patient’s purulent ulcerations were positive for HSV type 1, further strengthening a diagnosis of secondary eczema herpeticum, which occurs when patients have widespread HSV superinfecting pre-existing skin conditions such as atopic dermatitis, Darier disease, and Hailey-Hailey disease.^5-7 The lesions are characterized by a monomorphic eruption of umbilicated vesicles on an erythematous base. Lesions can progress to punched-out ulcers and erosions with hemorrhagic crusts that coalesce, forming scalloped borders, similar to our patient’s presentation.⁸

Hailey-Hailey disease, a genodermatosis that alters calcium signaling with an autosomal-dominant inheritance pattern, was unlikely in our patient due to the presence of nail abnormalities and palmar pits that are characteristic of Darier disease. From a purely histopathologic standpoint, Grover disease was considered with skin biopsy demonstrating acantholytic dyskeratosis but was not compatible with the clinical context. Furthermore, trials of antibiotics with group A Streptococcus and Staphylococcus aureus coverage failed in our patient, and she lacked systemic symptoms that would be supportive of a cellulitis diagnosis. The punched-out lesions suggested that an isolated exacerbation of atopic dermatitis was not sufficient to explain all of the clinical findings.

Eczema herpeticum must be considered in the differential diagnosis for patients with underlying Darier disease and widespread ulcerations. Our patient had more recent punched-out ulcerations in the intertriginous regions, with other areas showing later stages of confluent ulcers with scalloped borders. Delayed diagnosis and treatment of eczema herpeticum combined with severe Darier disease can lead to increased risk for hospitalization and rarely fatality.^8,9

Our patient was started on intravenous acyclovir until the lesions crusted and then was transitioned to a suppressive dose of oral valacyclovir given the widespread distribution. The Darier disease itself was managed with topical steroids and a zinc oxide barrier, serving as protectants to pathogens through microscopic breaks in the skin. Our patient also had a mild case of candidal intertrigo that was exacerbated by obesity and managed with topical ketoconazole. Gabapentin, hydromorphone, and acetaminophen were used for pain. She was discharged 10 days after admission with substantial improvement of both the HSV lesions and the irritation from her Darier disease. At follow-up visits 20 days later and again 6 months after discharge, she had been feeling well without any HSV flares.

The eczema herpeticum likely arose from our patient’s chronic skin barrier impairment attributed to Darier disease, leading to the cutaneous inoculation of HSV. Our patient and her family members had never been evaluated by a dermatologist until late in life during this hospitalization. Medication compliance with a suppressive dose of oral valacyclovir and topical steroids is vital to prevent flares of both eczema herpeticum and Darier disease, respectively. This case highlights the importance of dermatology consultation for complex cutaneous findings, as delayed diagnosis and treatment can lead to increased morbidity and mortality.

The Diagnosis: Superficial Angiomyxoma

Superficial angiomyxoma is a rare, benign, cutaneous tumor of a myxoid matrix and blood vessels that was first described in association with Carney complex.¹ Tumors may be solitary or multiple. A recent review of cases in the literature revealed a roughly equal distribution of superficial angiomyxomas in males and females occurring most frequently on the head and neck, extremities, and trunk or back. The peak incidence is between the fourth and fifth decades of life.² Superficial angiomyxomas can occur sporadically or in association with Carney complex, an autosomal-dominant condition with germline inactivating mutations in protein kinase A, PRKAR1A. Interestingly, sporadic cases of superficial angiomyxoma also have shown loss of PRKAR1A expression on immunohistochemistry (IHC).³

Common histologic mimics of superficial angiomyxoma include aggressive angiomyxoma and angiomyofibroblastoma.⁴ It is thought that these 3 distinct tumor entities may arise from a common pluripotent cell of origin located near connective tissue vasculature, which may contribute to the similarities observed between them.⁵ For example, aggressive angiomyxomas and angiomyofibroblastomas also demonstrate a similar myxoid background and vascular proliferation that can closely mimic superficial angiomyxomas clinically. However, the vessels of superficial angiomyxomas tend to be long and thin walled, while aggressive angiomyxomas are characterized by large and thick-walled vessels and angiomyofibroblastomas by abundant smaller vessels. Additionally, unlike superficial angiomyxomas, both aggressive angiomyxomas and angiomyofibroblastomas typically occur in the genital tract of young to middle-aged women.⁶

Histopathologic examination is imperative for differentiating between superficial angiomyxoma and more aggressive histologic mimics. Superficial angiomyxomas typically consist of a rich myxoid stroma, thin-walled or arborizing blood vessels, and spindled to stellate fibroblastlike cells (quiz image 2).³ Although not prominent in our case, superficial angiomyxomas also frequently present with stromal neutrophils and epithelial components, including keratinous cysts, basaloid buds, and strands of squamous epithelium.⁷ Minimal cellular atypia, mitotic activity, and nuclear pleomorphism often are seen, with IHC negative for desmin, estrogen receptor, and progesterone receptor; positive for CD34 and smooth muscle actin; and variable for S-100 and muscle-specific actin. Although IHC has limited utility in the diagnosis of superficial angiomyxomas, it may be useful to rule out other differential diagnoses.^2,3 Superficial angiomyxomas usually show fibroblastic stromal cells, proteoglycan matrix, and collagen fibers on electron microscopy.⁸ Importantly, histopathologic examination of aggressive angiomyxoma will comparatively present with more invasive, infiltrative, and less well-circumscribed tumors.⁹ Other differential diagnoses on histology may include neurofibroma, focal cutaneous mucinosis, spindle cell lipoma, and myxofibrosarcoma. Additional considerations include fibroepithelial polyp, nevus lipomatosis, angiomyxolipoma, and anetoderma.

An important differential diagnosis in the evaluation of superficial angiomyxoma is neurofibroma, a benign peripheral nerve sheath tumor that presents as a smooth, flesh-colored, and painless papule or nodule commonly associated with the buttonhole sign. Histopathology of neurofibroma features elongated spindle cells with comma-shaped or buckled wavy nuclei and variably sized collagen bundles described as “shredded carrots” (Figure 1).¹⁰ Occasional mast cells also can be seen. Immunohistochemistry targeting elements of peripheral nerve sheaths may assist in the diagnosis of neurofibromas, including positive S-100 and SOX10 in Schwann cells, epithelial membrane antigen in perineural cells, and fingerprint positivity for CD34 in fibroblasts.¹⁰

Cutaneous mucinoses encompass a diverse group of connective tissue disorders characterized by accumulation of mucin in the skin. Solitary focal cutaneous mucinoses (FCMs) are individual isolated lesions of mucin deposits that are unassociated with systemic conditions.¹¹ Conversely, multiple FCMs presenting with multiple cutaneous lesions also have been described in association with systemic diseases such as scleroderma, systemic lupus erythematosus, and thyroid disease.¹² Solitary FCM typically presents as an asymptomatic, flesh-colored papule or nodule on the extremities. It often arises in mid to late adulthood with a slightly increased frequency among males.¹² Histopathology of solitary FCM commonly demonstrates a dome-shaped pool of basophilic mucin in the upper dermis sparing involvement of the underlying subcutaneous tissue (Figure 2).¹³ Notably, FCM often lacks the vascularity as well as stromal neutrophils and epithelial elements that are seen in superficial angiomyxomas. Although hematoxylin and eosin stains can be sufficient for diagnosis of solitary FCM, additional stains for mucin such as Alcian blue, colloidal iron, or toluidine blue also may be considered to support the diagnosis.¹²

Spindle cell lipomas (SCLs) are rare, benign, subcutaneous, adipocytic tumors that arise on the upper back, posterior neck, or shoulders of middle-aged or elderly adult males.¹⁴ The clinical presentation often is an asymptomatic, well-circumscribed, mobile subcutaneous mass that is firmer than a common lipoma. Histologically, SCLs are characterized by mature adipocytes, spindle cells, and wire or ropelike collagen fibers in a myxoid background (Figure 3). The spindle cells usually are bland with a notable bipolar shape and blunted ends. Infiltrative growth patterns or mitotic figures are uncommon. Diagnosis can be supported by IHC, as SCLs stain diffusely positive for CD34 with loss of the retinoblastoma protein.⁷

Another important differential diagnosis to consider is myxofibrosarcoma, a rare and malignant myxoid cutaneous tumor. Clinically, it presents asymptomatically as an indolent, slow-growing nodule on the limbs and limb girdles.⁷ Histopathologic features demonstrate a multilobular tumor composed of a mixture of hypocellular and hypercellular regions with incomplete fibrous septae (Figure 4). The presence of curvilinear vasculature is characteristic. Multinucleated giant cells and cellular atypia with nuclear pleomorphism also can be seen. Although IHC findings generally are not specific, they can be used to rule out other potential diagnoses. Myxofibrosarcomas stain positive for vimentin and occasionally smooth muscle actin, muscle-specific actin, and CD34.⁷

Superficial angiomyxomas are benign; however, excision is recommended to distinguish between mimics. Local recurrence after excision is common in 30% to 40% of patients.¹⁵ Mohs micrographic surgery has been considered, especially if the following are present: tumor characteristics (eg, poorly circumscribed), location (eg, head and neck or other cosmetically or functionally sensitive areas), and likelihood of recurrence (high for superficial angiomyxomas). 16 This case otherwise highlights a rare example of superficial angiomyxomas involving the buttocks.

The Diagnosis: Superficial Angiomyxoma

Superficial angiomyxoma is a rare, benign, cutaneous tumor of a myxoid matrix and blood vessels that was first described in association with Carney complex.¹ Tumors may be solitary or multiple. A recent review of cases in the literature revealed a roughly equal distribution of superficial angiomyxomas in males and females occurring most frequently on the head and neck, extremities, and trunk or back. The peak incidence is between the fourth and fifth decades of life.² Superficial angiomyxomas can occur sporadically or in association with Carney complex, an autosomal-dominant condition with germline inactivating mutations in protein kinase A, PRKAR1A. Interestingly, sporadic cases of superficial angiomyxoma also have shown loss of PRKAR1A expression on immunohistochemistry (IHC).³

Common histologic mimics of superficial angiomyxoma include aggressive angiomyxoma and angiomyofibroblastoma.⁴ It is thought that these 3 distinct tumor entities may arise from a common pluripotent cell of origin located near connective tissue vasculature, which may contribute to the similarities observed between them.⁵ For example, aggressive angiomyxomas and angiomyofibroblastomas also demonstrate a similar myxoid background and vascular proliferation that can closely mimic superficial angiomyxomas clinically. However, the vessels of superficial angiomyxomas tend to be long and thin walled, while aggressive angiomyxomas are characterized by large and thick-walled vessels and angiomyofibroblastomas by abundant smaller vessels. Additionally, unlike superficial angiomyxomas, both aggressive angiomyxomas and angiomyofibroblastomas typically occur in the genital tract of young to middle-aged women.⁶

Histopathologic examination is imperative for differentiating between superficial angiomyxoma and more aggressive histologic mimics. Superficial angiomyxomas typically consist of a rich myxoid stroma, thin-walled or arborizing blood vessels, and spindled to stellate fibroblastlike cells (quiz image 2).³ Although not prominent in our case, superficial angiomyxomas also frequently present with stromal neutrophils and epithelial components, including keratinous cysts, basaloid buds, and strands of squamous epithelium.⁷ Minimal cellular atypia, mitotic activity, and nuclear pleomorphism often are seen, with IHC negative for desmin, estrogen receptor, and progesterone receptor; positive for CD34 and smooth muscle actin; and variable for S-100 and muscle-specific actin. Although IHC has limited utility in the diagnosis of superficial angiomyxomas, it may be useful to rule out other differential diagnoses.^2,3 Superficial angiomyxomas usually show fibroblastic stromal cells, proteoglycan matrix, and collagen fibers on electron microscopy.⁸ Importantly, histopathologic examination of aggressive angiomyxoma will comparatively present with more invasive, infiltrative, and less well-circumscribed tumors.⁹ Other differential diagnoses on histology may include neurofibroma, focal cutaneous mucinosis, spindle cell lipoma, and myxofibrosarcoma. Additional considerations include fibroepithelial polyp, nevus lipomatosis, angiomyxolipoma, and anetoderma.

An important differential diagnosis in the evaluation of superficial angiomyxoma is neurofibroma, a benign peripheral nerve sheath tumor that presents as a smooth, flesh-colored, and painless papule or nodule commonly associated with the buttonhole sign. Histopathology of neurofibroma features elongated spindle cells with comma-shaped or buckled wavy nuclei and variably sized collagen bundles described as “shredded carrots” (Figure 1).¹⁰ Occasional mast cells also can be seen. Immunohistochemistry targeting elements of peripheral nerve sheaths may assist in the diagnosis of neurofibromas, including positive S-100 and SOX10 in Schwann cells, epithelial membrane antigen in perineural cells, and fingerprint positivity for CD34 in fibroblasts.¹⁰

Cutaneous mucinoses encompass a diverse group of connective tissue disorders characterized by accumulation of mucin in the skin. Solitary focal cutaneous mucinoses (FCMs) are individual isolated lesions of mucin deposits that are unassociated with systemic conditions.¹¹ Conversely, multiple FCMs presenting with multiple cutaneous lesions also have been described in association with systemic diseases such as scleroderma, systemic lupus erythematosus, and thyroid disease.¹² Solitary FCM typically presents as an asymptomatic, flesh-colored papule or nodule on the extremities. It often arises in mid to late adulthood with a slightly increased frequency among males.¹² Histopathology of solitary FCM commonly demonstrates a dome-shaped pool of basophilic mucin in the upper dermis sparing involvement of the underlying subcutaneous tissue (Figure 2).¹³ Notably, FCM often lacks the vascularity as well as stromal neutrophils and epithelial elements that are seen in superficial angiomyxomas. Although hematoxylin and eosin stains can be sufficient for diagnosis of solitary FCM, additional stains for mucin such as Alcian blue, colloidal iron, or toluidine blue also may be considered to support the diagnosis.¹²

Spindle cell lipomas (SCLs) are rare, benign, subcutaneous, adipocytic tumors that arise on the upper back, posterior neck, or shoulders of middle-aged or elderly adult males.¹⁴ The clinical presentation often is an asymptomatic, well-circumscribed, mobile subcutaneous mass that is firmer than a common lipoma. Histologically, SCLs are characterized by mature adipocytes, spindle cells, and wire or ropelike collagen fibers in a myxoid background (Figure 3). The spindle cells usually are bland with a notable bipolar shape and blunted ends. Infiltrative growth patterns or mitotic figures are uncommon. Diagnosis can be supported by IHC, as SCLs stain diffusely positive for CD34 with loss of the retinoblastoma protein.⁷

Another important differential diagnosis to consider is myxofibrosarcoma, a rare and malignant myxoid cutaneous tumor. Clinically, it presents asymptomatically as an indolent, slow-growing nodule on the limbs and limb girdles.⁷ Histopathologic features demonstrate a multilobular tumor composed of a mixture of hypocellular and hypercellular regions with incomplete fibrous septae (Figure 4). The presence of curvilinear vasculature is characteristic. Multinucleated giant cells and cellular atypia with nuclear pleomorphism also can be seen. Although IHC findings generally are not specific, they can be used to rule out other potential diagnoses. Myxofibrosarcomas stain positive for vimentin and occasionally smooth muscle actin, muscle-specific actin, and CD34.⁷

Superficial angiomyxomas are benign; however, excision is recommended to distinguish between mimics. Local recurrence after excision is common in 30% to 40% of patients.¹⁵ Mohs micrographic surgery has been considered, especially if the following are present: tumor characteristics (eg, poorly circumscribed), location (eg, head and neck or other cosmetically or functionally sensitive areas), and likelihood of recurrence (high for superficial angiomyxomas). 16 This case otherwise highlights a rare example of superficial angiomyxomas involving the buttocks.

The Diagnosis: Superficial Angiomyxoma

Superficial angiomyxoma is a rare, benign, cutaneous tumor of a myxoid matrix and blood vessels that was first described in association with Carney complex.¹ Tumors may be solitary or multiple. A recent review of cases in the literature revealed a roughly equal distribution of superficial angiomyxomas in males and females occurring most frequently on the head and neck, extremities, and trunk or back. The peak incidence is between the fourth and fifth decades of life.² Superficial angiomyxomas can occur sporadically or in association with Carney complex, an autosomal-dominant condition with germline inactivating mutations in protein kinase A, PRKAR1A. Interestingly, sporadic cases of superficial angiomyxoma also have shown loss of PRKAR1A expression on immunohistochemistry (IHC).³

Common histologic mimics of superficial angiomyxoma include aggressive angiomyxoma and angiomyofibroblastoma.⁴ It is thought that these 3 distinct tumor entities may arise from a common pluripotent cell of origin located near connective tissue vasculature, which may contribute to the similarities observed between them.⁵ For example, aggressive angiomyxomas and angiomyofibroblastomas also demonstrate a similar myxoid background and vascular proliferation that can closely mimic superficial angiomyxomas clinically. However, the vessels of superficial angiomyxomas tend to be long and thin walled, while aggressive angiomyxomas are characterized by large and thick-walled vessels and angiomyofibroblastomas by abundant smaller vessels. Additionally, unlike superficial angiomyxomas, both aggressive angiomyxomas and angiomyofibroblastomas typically occur in the genital tract of young to middle-aged women.⁶

Histopathologic examination is imperative for differentiating between superficial angiomyxoma and more aggressive histologic mimics. Superficial angiomyxomas typically consist of a rich myxoid stroma, thin-walled or arborizing blood vessels, and spindled to stellate fibroblastlike cells (quiz image 2).³ Although not prominent in our case, superficial angiomyxomas also frequently present with stromal neutrophils and epithelial components, including keratinous cysts, basaloid buds, and strands of squamous epithelium.⁷ Minimal cellular atypia, mitotic activity, and nuclear pleomorphism often are seen, with IHC negative for desmin, estrogen receptor, and progesterone receptor; positive for CD34 and smooth muscle actin; and variable for S-100 and muscle-specific actin. Although IHC has limited utility in the diagnosis of superficial angiomyxomas, it may be useful to rule out other differential diagnoses.^2,3 Superficial angiomyxomas usually show fibroblastic stromal cells, proteoglycan matrix, and collagen fibers on electron microscopy.⁸ Importantly, histopathologic examination of aggressive angiomyxoma will comparatively present with more invasive, infiltrative, and less well-circumscribed tumors.⁹ Other differential diagnoses on histology may include neurofibroma, focal cutaneous mucinosis, spindle cell lipoma, and myxofibrosarcoma. Additional considerations include fibroepithelial polyp, nevus lipomatosis, angiomyxolipoma, and anetoderma.

An important differential diagnosis in the evaluation of superficial angiomyxoma is neurofibroma, a benign peripheral nerve sheath tumor that presents as a smooth, flesh-colored, and painless papule or nodule commonly associated with the buttonhole sign. Histopathology of neurofibroma features elongated spindle cells with comma-shaped or buckled wavy nuclei and variably sized collagen bundles described as “shredded carrots” (Figure 1).¹⁰ Occasional mast cells also can be seen. Immunohistochemistry targeting elements of peripheral nerve sheaths may assist in the diagnosis of neurofibromas, including positive S-100 and SOX10 in Schwann cells, epithelial membrane antigen in perineural cells, and fingerprint positivity for CD34 in fibroblasts.¹⁰

Cutaneous mucinoses encompass a diverse group of connective tissue disorders characterized by accumulation of mucin in the skin. Solitary focal cutaneous mucinoses (FCMs) are individual isolated lesions of mucin deposits that are unassociated with systemic conditions.¹¹ Conversely, multiple FCMs presenting with multiple cutaneous lesions also have been described in association with systemic diseases such as scleroderma, systemic lupus erythematosus, and thyroid disease.¹² Solitary FCM typically presents as an asymptomatic, flesh-colored papule or nodule on the extremities. It often arises in mid to late adulthood with a slightly increased frequency among males.¹² Histopathology of solitary FCM commonly demonstrates a dome-shaped pool of basophilic mucin in the upper dermis sparing involvement of the underlying subcutaneous tissue (Figure 2).¹³ Notably, FCM often lacks the vascularity as well as stromal neutrophils and epithelial elements that are seen in superficial angiomyxomas. Although hematoxylin and eosin stains can be sufficient for diagnosis of solitary FCM, additional stains for mucin such as Alcian blue, colloidal iron, or toluidine blue also may be considered to support the diagnosis.¹²

Spindle cell lipomas (SCLs) are rare, benign, subcutaneous, adipocytic tumors that arise on the upper back, posterior neck, or shoulders of middle-aged or elderly adult males.¹⁴ The clinical presentation often is an asymptomatic, well-circumscribed, mobile subcutaneous mass that is firmer than a common lipoma. Histologically, SCLs are characterized by mature adipocytes, spindle cells, and wire or ropelike collagen fibers in a myxoid background (Figure 3). The spindle cells usually are bland with a notable bipolar shape and blunted ends. Infiltrative growth patterns or mitotic figures are uncommon. Diagnosis can be supported by IHC, as SCLs stain diffusely positive for CD34 with loss of the retinoblastoma protein.⁷

Another important differential diagnosis to consider is myxofibrosarcoma, a rare and malignant myxoid cutaneous tumor. Clinically, it presents asymptomatically as an indolent, slow-growing nodule on the limbs and limb girdles.⁷ Histopathologic features demonstrate a multilobular tumor composed of a mixture of hypocellular and hypercellular regions with incomplete fibrous septae (Figure 4). The presence of curvilinear vasculature is characteristic. Multinucleated giant cells and cellular atypia with nuclear pleomorphism also can be seen. Although IHC findings generally are not specific, they can be used to rule out other potential diagnoses. Myxofibrosarcomas stain positive for vimentin and occasionally smooth muscle actin, muscle-specific actin, and CD34.⁷

Superficial angiomyxomas are benign; however, excision is recommended to distinguish between mimics. Local recurrence after excision is common in 30% to 40% of patients.¹⁵ Mohs micrographic surgery has been considered, especially if the following are present: tumor characteristics (eg, poorly circumscribed), location (eg, head and neck or other cosmetically or functionally sensitive areas), and likelihood of recurrence (high for superficial angiomyxomas). 16 This case otherwise highlights a rare example of superficial angiomyxomas involving the buttocks.

To reach early diagnoses and improve outcomes in cases of mucosal and esophageal lichen planus (ELP), patient education along with a multidisciplinary approach centered on collaboration among dermatologists, gastroenterologists, gynecologists, and dental practitioners should be a priority. Tofacitinib therapy should be considered in the treatment of patients presenting with cutaneous lichen planus (CLP), mucosal lichen planus, and ELP.

Lichen planus is a papulosquamous disease of the skin and mucous membranes that is most common on the skin and oral mucosa. Typical lesions of CLP present as purple, pruritic, polygonal papules and plaques on the flexural surfaces of the wrists and ankles as well as areas of friction or trauma due to scratching such as the shins and lower back. Various subtypes of lichen planus can present simultaneously, resulting in extensive involvement that worsens through koebnerization and affects the oral cavity, esophagus, larynx, sclera, genitalia, scalp, and nails.^1,2

Esophageal lichen planus can develop with or without the presence of CLP, oral lichen planus (OLP), or genital lichen planus.³ It typically affects women older than 50 years and is linked to OLP and vulvar lichen planus, with 1 study reporting that 87% (63/72) of ELP patients were women with a median age of 61.9 years at the time of diagnosis (range, 22–85 years). Almost all ELP patients in the study had lichen planus symptoms in other locations; 89% (64/72) had OLP, and 42% (30/72) had vulvar lichen planus.⁴ Consequently, a diagnosis of ELP should be followed by a thorough full-body examination to check for lichen planus at other sites. Studies that examined lichen planus patients for ELP found that 25% to 50% of patients diagnosed with orocutaneous lichen planus also had ELP, with ELP frequently presenting without symptoms.^3,5 These findings indicate that ELP likely is underdiagnosed and often misdiagnosed, resulting in an underestimation of its prevalence.

Our case highlights a frequently misdiagnosed condition and underscores the importance of close examination of patients presenting with CLP and OLP for signs and symptoms of ELP. Furthermore, we discuss the importance of patient education and collaboration among different specialties in attaining an early diagnosis to improve patient outcomes. Finally, we review the clinical presentation, diagnosis, and treatment of CLP, OLP, and ELP, as well as the utility of tofacitinib for ELP.

Case Report

An emaciated 89-year-old woman with an 11-year history of CLP, OLP, and genital lichen planus that had been successfully treated with topicals presented with an OLP recurrence alongside difficulties eating and swallowing. Her symptoms lasted 1 year and would recur when treatment was paused. Her medical history included rheumatoid arthritis, hypothyroidism, and hypertension, and she was taking levothyroxine, olmesartan, and vitamin D supplements. Dentures and olmesartan previously were ruled out as potential triggers following a 2-month elimination. None of her remaining natural teeth had fillings. She also reported that neither she nor her partner had ever smoked or chewed tobacco.

The patient’s lichen planus involvement first manifested as red, itchy, polygonal, lichenoid papules on the superior and inferior mid back 11 years prior to the current presentation (Figure 1). Further examination noted erosions on the genitalia, and a subsequent biopsy of the vulva confirmed a diagnosis of lichen planus (Figure 2). Treatment with halobetasol propionate ointment and tacrolimus ointment 0.1% twice daily (BID) resulted in remission of the CLP and vulvar lichen planus. She presented a year later with oral involvement revealing Wickham striae on the buccal mucosa and erosions on the upper palate that resolved after 2 months of treatment with cyclosporine oral solution mixed with a 5-times-daily nystatin swish-and-spit (Figure 3). The CLP did not recur but OLP was punctuated by remissions and recurrences on a yearly basis, often related to the cessation of mouthwash and topical creams. The OLP and vulvar lichen planus were successfully treated with as-needed use of a cyclosporine mouthwash swish-and-spit 3 times daily as well as halobetasol ointment 0.05% 3 times daily, respectively. Six years later, the patient was hospitalized for unrelated causes and was lost to follow-up for 2 years.

The patient experienced worsening dysphagia and odynophagia over a period of 2 years (mild dysphagia was first recorded 7 years prior to the initial presentation) and reported an unintentional weight loss of 20 pounds. An endoscopy was performed 3 years after the initial report of dysphagia and noted esophageal erosions (Figure 4A) and a stricture (Figure 4B), but all abnormal involvement was attributed to active gastroesophageal reflux disease. She underwent 8 esophageal dilations to treat the stricture but noted that the duration of symptomatic relief decreased with every subsequent dilation. An esophageal stent was placed 4 years after the initial concern of dysphagia, but it was not well tolerated and had to be removed soon thereafter. A year later, the patient underwent an esophageal bypass with a substernal gastric conduit that provided relief for 2 months but failed to permanently resolve the condition. In fact, her condition worsened over the next 1.5 years when she presented with extreme emaciation attributed to a low appetite and pain while eating. A review of the slides from a prior hospital esophageal biopsy revealed lichen planus (Figure 5). She was prescribed tofacitinib 5 mg BID as a dual-purpose treatment for the rheumatoid arthritis and OLP/ELP. At 1-month follow-up she noted that she had only taken one 5-mg pill daily without notable improvement, and after the visit she started the initial recommendation of 5 mg BID. Over the next several months, her condition continued to consistently improve; the odynophagia resolved, and she regained the majority of her lost weight. Tofacitinib was well tolerated across the course of treatment, and no adverse side effects were noted. Furthermore, the patient regained a full range of motion in the previously immobile arthritic right shoulder. She has experienced no recurrence of the genital lichen planus, OLP, or CLP since starting tofacitinib. To date, the patient is still taking only tofacitinib 5 mg BID with no recurrence of the cutaneous, mucosal, or esophageal lichen planus and has experienced no adverse events from the medication.

Clinical Presentation—Lichen planus—CLP and OLP—most frequently presents between the ages of 40 and 60 years, with a slight female predilection.^1,2 The lesions typically present with the 5 P’s—purple, pruritic, polygonal papules and plaques—with some lesions revealing white lacy lines overlying them called Wickham striae.⁶ The lesions may be red at first before turning purple. They often present on the flexural surfaces of the wrists and ankles as well as the shins and back but rarely affect the face, perhaps because of increased chronic sun exposure.^2,6 Less common locations include the scalp, nails, and mucosal areas (eg, oral, vulvar, conjunctival, laryngeal, esophageal, anal).¹

If CLP is diagnosed, the patient likely will also have oral lesions, which occur in 50% of patients.² Once any form of lichen planus is found, it is important to examine all of the most frequently involved locations—mucocutaneous and cutaneous as well as the nails and scalp. Special care should be taken when examining OLP and genital lichen planus, as long-standing lesions have a 2% to 5% chance of transforming into squamous cell carcinoma.²

Although cases of traditional OLP and CLP are ubiquitous in the literature, ELP rarely is documented because of frequent misdiagnoses. Esophageal lichen planus has a closer histopathologic resemblance to OLP compared to CLP, and its highly variable presentation often results in an inconclusive diagnosis.³ A review of 27 patients with lichen planus highlighted the difficult nature of diagnosing ELP; ELP manifested up to 20 years after initial lichen planus diagnosis, and patients underwent an average of 2.5 dilations prior to the successful diagnosis of ELP. Interestingly, 2 patients in the study presented with ELP in isolation, which emphasizes the importance of secondary examination for lichen planus in the presence of esophageal strictures.⁷ The eTable provides common patient demographics and symptoms to more effectively identify ELP.Differential Diagnosis—Because lichen planus can present anywhere on the body, it may be difficult to differentiate it from other skin conditions. Clinical appearance alone often is insufficient for diagnosing lichen planus, and a punch biopsy often is needed.^2,20 Cutaneous lichen planus may resemble eczema, lichen simplex chronicus, pityriasis rosea, prurigo nodularis, and psoriasis, while OLP may resemble bite trauma, leukoplakia, pemphigus, and thrush.²⁰ Dermoscopy of the tissue makes Wickham striae easier to visualize and assists in the diagnosis of lichen planus. Furthermore, thickening of the stratum granulosum, a prevalence of lymphocytes in the dermoepidermal junction, and vacuolar alteration of the stratum basale help to distinguish between lichen planus and other inflammatory dermatoses.²⁰ A diagnosis of lichen planus merits a full-body skin examination—hair, nails, eyes, oral mucosa, and genitalia—to rule out additional involvement.

Esophageal lichen planus most frequently presents as dysphagia, odynophagia, and weight loss, but other symptoms including heartburn, hoarseness, choking, and epigastric pain may suggest esophageal involvement.⁴ Typically, ELP presents in the proximal and/or central esophagus, assisting in the differentiation between ELP and other esophageal conditions.³ Special consideration should be taken when both ELP and gastroesophageal reflux disease are considered in a differential diagnosis, and it is recommended to pair an upper endoscopy with pH monitoring to avoid misdiagnosis.⁸ Screening endoscopies also are helpful, as they assist in identifying the characteristic white webs, skin peeling, skin surface erosion, and strictures of ELP.⁴ Taken together, dermatologists should encourage patients with cutaneous or mucocutaneous lichen planus to undergo an esophagogastroduodenoscopy, especially in the presence of any of ELP’s common symptoms (eTable).

Etiology—Although the exact etiology of lichen planus is not well established, there are several known correlative factors, including hepatitis C; increased stress; dental materials; oral medications, most frequently antihypertensives and nonsteroidal anti-inflammatory drugs; systemic diseases; and tobacco usage.^6,21

Dental materials used in oral treatments such as silver amalgam, gold, cobalt, palladium, chromium, epoxy resins, and dentures can trigger or exacerbate OLP, and patch testing of a patient’s dental materials can help determine if the reaction was caused by the materials.^6,22 The removal of material contributing to lesions often will cause OLP to resolve.²²

It also has been suggested that the presence of thyroid disorders, autoimmune disease, various cancers, hypertension, type 2 diabetes mellitus, hyperlipidemia, oral sedative usage, and/or vitamin D deficiency may be associated with OLP.^21,23 Although OLP patients who were initially deficient in vitamin D demonstrated marked improvement with supplementation, it is unlikely that vitamin D supplements impacted our patient’s presentation of OLP, as she had been consistently taking them for more than 5 years with no change in OLP presentation.²⁴

Pathogenesis—Lichen planus is thought to be a cytotoxic CD8⁺ T cell–mediated autoimmune disease to a virally modified epidermal self-antigen on keratinocytes. The cytotoxic T cells target the modified self-antigens on basal keratinocytes and induce apoptosis.²⁵ The cytokine-mediated lymphocyte homing mechanism is human leukocyte antigen dependent and involves tumor necrosis factor α as well as IFN-γ and IL-1. The latter cytokines lead to upregulation of vascular adhesion molecules on endothelial vessels of subepithelial vascular plexus as well as a cascade of nonspecific mechanisms such as mast cell degranulation and matrix metalloproteinase activation, resulting in increased basement membrane disruption.⁶

Shao et al¹⁹ underscored the role of IFN-γ in CD8⁺ T cell–mediated cytotoxic cellular responses, noting that the Janus kinase (JAK)–signal transducer and activator of transcription pathway may play a key role in the pathogenesis of lichen planus. They proposed using JAK inhibitors for the treatment of lichen planus, specifically tofacitinib, a JAK1/JAK3 inhibitor, and baricitinib, a JAK1/JAK2 inhibitor, as top therapeutic agents for lichen planus (eTable).¹⁹ Tofacitinib has been reported to successfully treat conditions such as psoriasis, psoriatic arthritis, alopecia areata, vitiligo, atopic dermatitis, sarcoidosis, pyoderma gangrenosum, and lichen planopilaris.²⁶ Additionally, the efficacy of tofacitinib has been established in patients with erosive lichen planus; tofacitinib resulted in marked improvement while prednisone, acitretin, methotrexate, mycophenolate mofetil, and cyclosporine treatment failed.²⁷ Although more studies on tofacitinib’s long-term efficacy, cost, and safety are necessary, tofacitinib may soon play an integral role in the battle against inflammatory dermatoses.

Conclusion

Esophageal lichen planus is an underreported form of lichen planus that often is misdiagnosed. It frequently causes dysphagia and odynophagia, resulting in a major decrease in a patient’s quality of life. We present the case of an 89-year-old woman who underwent procedures to dilate her esophagus that worsened her condition. We emphasize the importance of considering ELP in the differential diagnosis of patients presenting with lichen planus in another region. In our patient, tofacitinib 5 mg BID resolved her condition without any adverse effects.

To reach early diagnoses and improve outcomes in cases of mucosal and esophageal lichen planus (ELP), patient education along with a multidisciplinary approach centered on collaboration among dermatologists, gastroenterologists, gynecologists, and dental practitioners should be a priority. Tofacitinib therapy should be considered in the treatment of patients presenting with cutaneous lichen planus (CLP), mucosal lichen planus, and ELP.

Lichen planus is a papulosquamous disease of the skin and mucous membranes that is most common on the skin and oral mucosa. Typical lesions of CLP present as purple, pruritic, polygonal papules and plaques on the flexural surfaces of the wrists and ankles as well as areas of friction or trauma due to scratching such as the shins and lower back. Various subtypes of lichen planus can present simultaneously, resulting in extensive involvement that worsens through koebnerization and affects the oral cavity, esophagus, larynx, sclera, genitalia, scalp, and nails.^1,2

Esophageal lichen planus can develop with or without the presence of CLP, oral lichen planus (OLP), or genital lichen planus.³ It typically affects women older than 50 years and is linked to OLP and vulvar lichen planus, with 1 study reporting that 87% (63/72) of ELP patients were women with a median age of 61.9 years at the time of diagnosis (range, 22–85 years). Almost all ELP patients in the study had lichen planus symptoms in other locations; 89% (64/72) had OLP, and 42% (30/72) had vulvar lichen planus.⁴ Consequently, a diagnosis of ELP should be followed by a thorough full-body examination to check for lichen planus at other sites. Studies that examined lichen planus patients for ELP found that 25% to 50% of patients diagnosed with orocutaneous lichen planus also had ELP, with ELP frequently presenting without symptoms.^3,5 These findings indicate that ELP likely is underdiagnosed and often misdiagnosed, resulting in an underestimation of its prevalence.

Our case highlights a frequently misdiagnosed condition and underscores the importance of close examination of patients presenting with CLP and OLP for signs and symptoms of ELP. Furthermore, we discuss the importance of patient education and collaboration among different specialties in attaining an early diagnosis to improve patient outcomes. Finally, we review the clinical presentation, diagnosis, and treatment of CLP, OLP, and ELP, as well as the utility of tofacitinib for ELP.

Case Report

An emaciated 89-year-old woman with an 11-year history of CLP, OLP, and genital lichen planus that had been successfully treated with topicals presented with an OLP recurrence alongside difficulties eating and swallowing. Her symptoms lasted 1 year and would recur when treatment was paused. Her medical history included rheumatoid arthritis, hypothyroidism, and hypertension, and she was taking levothyroxine, olmesartan, and vitamin D supplements. Dentures and olmesartan previously were ruled out as potential triggers following a 2-month elimination. None of her remaining natural teeth had fillings. She also reported that neither she nor her partner had ever smoked or chewed tobacco.

The patient’s lichen planus involvement first manifested as red, itchy, polygonal, lichenoid papules on the superior and inferior mid back 11 years prior to the current presentation (Figure 1). Further examination noted erosions on the genitalia, and a subsequent biopsy of the vulva confirmed a diagnosis of lichen planus (Figure 2). Treatment with halobetasol propionate ointment and tacrolimus ointment 0.1% twice daily (BID) resulted in remission of the CLP and vulvar lichen planus. She presented a year later with oral involvement revealing Wickham striae on the buccal mucosa and erosions on the upper palate that resolved after 2 months of treatment with cyclosporine oral solution mixed with a 5-times-daily nystatin swish-and-spit (Figure 3). The CLP did not recur but OLP was punctuated by remissions and recurrences on a yearly basis, often related to the cessation of mouthwash and topical creams. The OLP and vulvar lichen planus were successfully treated with as-needed use of a cyclosporine mouthwash swish-and-spit 3 times daily as well as halobetasol ointment 0.05% 3 times daily, respectively. Six years later, the patient was hospitalized for unrelated causes and was lost to follow-up for 2 years.

The patient experienced worsening dysphagia and odynophagia over a period of 2 years (mild dysphagia was first recorded 7 years prior to the initial presentation) and reported an unintentional weight loss of 20 pounds. An endoscopy was performed 3 years after the initial report of dysphagia and noted esophageal erosions (Figure 4A) and a stricture (Figure 4B), but all abnormal involvement was attributed to active gastroesophageal reflux disease. She underwent 8 esophageal dilations to treat the stricture but noted that the duration of symptomatic relief decreased with every subsequent dilation. An esophageal stent was placed 4 years after the initial concern of dysphagia, but it was not well tolerated and had to be removed soon thereafter. A year later, the patient underwent an esophageal bypass with a substernal gastric conduit that provided relief for 2 months but failed to permanently resolve the condition. In fact, her condition worsened over the next 1.5 years when she presented with extreme emaciation attributed to a low appetite and pain while eating. A review of the slides from a prior hospital esophageal biopsy revealed lichen planus (Figure 5). She was prescribed tofacitinib 5 mg BID as a dual-purpose treatment for the rheumatoid arthritis and OLP/ELP. At 1-month follow-up she noted that she had only taken one 5-mg pill daily without notable improvement, and after the visit she started the initial recommendation of 5 mg BID. Over the next several months, her condition continued to consistently improve; the odynophagia resolved, and she regained the majority of her lost weight. Tofacitinib was well tolerated across the course of treatment, and no adverse side effects were noted. Furthermore, the patient regained a full range of motion in the previously immobile arthritic right shoulder. She has experienced no recurrence of the genital lichen planus, OLP, or CLP since starting tofacitinib. To date, the patient is still taking only tofacitinib 5 mg BID with no recurrence of the cutaneous, mucosal, or esophageal lichen planus and has experienced no adverse events from the medication.

Clinical Presentation—Lichen planus—CLP and OLP—most frequently presents between the ages of 40 and 60 years, with a slight female predilection.^1,2 The lesions typically present with the 5 P’s—purple, pruritic, polygonal papules and plaques—with some lesions revealing white lacy lines overlying them called Wickham striae.⁶ The lesions may be red at first before turning purple. They often present on the flexural surfaces of the wrists and ankles as well as the shins and back but rarely affect the face, perhaps because of increased chronic sun exposure.^2,6 Less common locations include the scalp, nails, and mucosal areas (eg, oral, vulvar, conjunctival, laryngeal, esophageal, anal).¹

If CLP is diagnosed, the patient likely will also have oral lesions, which occur in 50% of patients.² Once any form of lichen planus is found, it is important to examine all of the most frequently involved locations—mucocutaneous and cutaneous as well as the nails and scalp. Special care should be taken when examining OLP and genital lichen planus, as long-standing lesions have a 2% to 5% chance of transforming into squamous cell carcinoma.²

Although cases of traditional OLP and CLP are ubiquitous in the literature, ELP rarely is documented because of frequent misdiagnoses. Esophageal lichen planus has a closer histopathologic resemblance to OLP compared to CLP, and its highly variable presentation often results in an inconclusive diagnosis.³ A review of 27 patients with lichen planus highlighted the difficult nature of diagnosing ELP; ELP manifested up to 20 years after initial lichen planus diagnosis, and patients underwent an average of 2.5 dilations prior to the successful diagnosis of ELP. Interestingly, 2 patients in the study presented with ELP in isolation, which emphasizes the importance of secondary examination for lichen planus in the presence of esophageal strictures.⁷ The eTable provides common patient demographics and symptoms to more effectively identify ELP.Differential Diagnosis—Because lichen planus can present anywhere on the body, it may be difficult to differentiate it from other skin conditions. Clinical appearance alone often is insufficient for diagnosing lichen planus, and a punch biopsy often is needed.^2,20 Cutaneous lichen planus may resemble eczema, lichen simplex chronicus, pityriasis rosea, prurigo nodularis, and psoriasis, while OLP may resemble bite trauma, leukoplakia, pemphigus, and thrush.²⁰ Dermoscopy of the tissue makes Wickham striae easier to visualize and assists in the diagnosis of lichen planus. Furthermore, thickening of the stratum granulosum, a prevalence of lymphocytes in the dermoepidermal junction, and vacuolar alteration of the stratum basale help to distinguish between lichen planus and other inflammatory dermatoses.²⁰ A diagnosis of lichen planus merits a full-body skin examination—hair, nails, eyes, oral mucosa, and genitalia—to rule out additional involvement.

Esophageal lichen planus most frequently presents as dysphagia, odynophagia, and weight loss, but other symptoms including heartburn, hoarseness, choking, and epigastric pain may suggest esophageal involvement.⁴ Typically, ELP presents in the proximal and/or central esophagus, assisting in the differentiation between ELP and other esophageal conditions.³ Special consideration should be taken when both ELP and gastroesophageal reflux disease are considered in a differential diagnosis, and it is recommended to pair an upper endoscopy with pH monitoring to avoid misdiagnosis.⁸ Screening endoscopies also are helpful, as they assist in identifying the characteristic white webs, skin peeling, skin surface erosion, and strictures of ELP.⁴ Taken together, dermatologists should encourage patients with cutaneous or mucocutaneous lichen planus to undergo an esophagogastroduodenoscopy, especially in the presence of any of ELP’s common symptoms (eTable).

Etiology—Although the exact etiology of lichen planus is not well established, there are several known correlative factors, including hepatitis C; increased stress; dental materials; oral medications, most frequently antihypertensives and nonsteroidal anti-inflammatory drugs; systemic diseases; and tobacco usage.^6,21

Dental materials used in oral treatments such as silver amalgam, gold, cobalt, palladium, chromium, epoxy resins, and dentures can trigger or exacerbate OLP, and patch testing of a patient’s dental materials can help determine if the reaction was caused by the materials.^6,22 The removal of material contributing to lesions often will cause OLP to resolve.²²

It also has been suggested that the presence of thyroid disorders, autoimmune disease, various cancers, hypertension, type 2 diabetes mellitus, hyperlipidemia, oral sedative usage, and/or vitamin D deficiency may be associated with OLP.^21,23 Although OLP patients who were initially deficient in vitamin D demonstrated marked improvement with supplementation, it is unlikely that vitamin D supplements impacted our patient’s presentation of OLP, as she had been consistently taking them for more than 5 years with no change in OLP presentation.²⁴

Pathogenesis—Lichen planus is thought to be a cytotoxic CD8⁺ T cell–mediated autoimmune disease to a virally modified epidermal self-antigen on keratinocytes. The cytotoxic T cells target the modified self-antigens on basal keratinocytes and induce apoptosis.²⁵ The cytokine-mediated lymphocyte homing mechanism is human leukocyte antigen dependent and involves tumor necrosis factor α as well as IFN-γ and IL-1. The latter cytokines lead to upregulation of vascular adhesion molecules on endothelial vessels of subepithelial vascular plexus as well as a cascade of nonspecific mechanisms such as mast cell degranulation and matrix metalloproteinase activation, resulting in increased basement membrane disruption.⁶

Shao et al¹⁹ underscored the role of IFN-γ in CD8⁺ T cell–mediated cytotoxic cellular responses, noting that the Janus kinase (JAK)–signal transducer and activator of transcription pathway may play a key role in the pathogenesis of lichen planus. They proposed using JAK inhibitors for the treatment of lichen planus, specifically tofacitinib, a JAK1/JAK3 inhibitor, and baricitinib, a JAK1/JAK2 inhibitor, as top therapeutic agents for lichen planus (eTable).¹⁹ Tofacitinib has been reported to successfully treat conditions such as psoriasis, psoriatic arthritis, alopecia areata, vitiligo, atopic dermatitis, sarcoidosis, pyoderma gangrenosum, and lichen planopilaris.²⁶ Additionally, the efficacy of tofacitinib has been established in patients with erosive lichen planus; tofacitinib resulted in marked improvement while prednisone, acitretin, methotrexate, mycophenolate mofetil, and cyclosporine treatment failed.²⁷ Although more studies on tofacitinib’s long-term efficacy, cost, and safety are necessary, tofacitinib may soon play an integral role in the battle against inflammatory dermatoses.

Conclusion

Esophageal lichen planus is an underreported form of lichen planus that often is misdiagnosed. It frequently causes dysphagia and odynophagia, resulting in a major decrease in a patient’s quality of life. We present the case of an 89-year-old woman who underwent procedures to dilate her esophagus that worsened her condition. We emphasize the importance of considering ELP in the differential diagnosis of patients presenting with lichen planus in another region. In our patient, tofacitinib 5 mg BID resolved her condition without any adverse effects.

To reach early diagnoses and improve outcomes in cases of mucosal and esophageal lichen planus (ELP), patient education along with a multidisciplinary approach centered on collaboration among dermatologists, gastroenterologists, gynecologists, and dental practitioners should be a priority. Tofacitinib therapy should be considered in the treatment of patients presenting with cutaneous lichen planus (CLP), mucosal lichen planus, and ELP.

Lichen planus is a papulosquamous disease of the skin and mucous membranes that is most common on the skin and oral mucosa. Typical lesions of CLP present as purple, pruritic, polygonal papules and plaques on the flexural surfaces of the wrists and ankles as well as areas of friction or trauma due to scratching such as the shins and lower back. Various subtypes of lichen planus can present simultaneously, resulting in extensive involvement that worsens through koebnerization and affects the oral cavity, esophagus, larynx, sclera, genitalia, scalp, and nails.^1,2

Esophageal lichen planus can develop with or without the presence of CLP, oral lichen planus (OLP), or genital lichen planus.³ It typically affects women older than 50 years and is linked to OLP and vulvar lichen planus, with 1 study reporting that 87% (63/72) of ELP patients were women with a median age of 61.9 years at the time of diagnosis (range, 22–85 years). Almost all ELP patients in the study had lichen planus symptoms in other locations; 89% (64/72) had OLP, and 42% (30/72) had vulvar lichen planus.⁴ Consequently, a diagnosis of ELP should be followed by a thorough full-body examination to check for lichen planus at other sites. Studies that examined lichen planus patients for ELP found that 25% to 50% of patients diagnosed with orocutaneous lichen planus also had ELP, with ELP frequently presenting without symptoms.^3,5 These findings indicate that ELP likely is underdiagnosed and often misdiagnosed, resulting in an underestimation of its prevalence.

Our case highlights a frequently misdiagnosed condition and underscores the importance of close examination of patients presenting with CLP and OLP for signs and symptoms of ELP. Furthermore, we discuss the importance of patient education and collaboration among different specialties in attaining an early diagnosis to improve patient outcomes. Finally, we review the clinical presentation, diagnosis, and treatment of CLP, OLP, and ELP, as well as the utility of tofacitinib for ELP.

Case Report

An emaciated 89-year-old woman with an 11-year history of CLP, OLP, and genital lichen planus that had been successfully treated with topicals presented with an OLP recurrence alongside difficulties eating and swallowing. Her symptoms lasted 1 year and would recur when treatment was paused. Her medical history included rheumatoid arthritis, hypothyroidism, and hypertension, and she was taking levothyroxine, olmesartan, and vitamin D supplements. Dentures and olmesartan previously were ruled out as potential triggers following a 2-month elimination. None of her remaining natural teeth had fillings. She also reported that neither she nor her partner had ever smoked or chewed tobacco.

The patient’s lichen planus involvement first manifested as red, itchy, polygonal, lichenoid papules on the superior and inferior mid back 11 years prior to the current presentation (Figure 1). Further examination noted erosions on the genitalia, and a subsequent biopsy of the vulva confirmed a diagnosis of lichen planus (Figure 2). Treatment with halobetasol propionate ointment and tacrolimus ointment 0.1% twice daily (BID) resulted in remission of the CLP and vulvar lichen planus. She presented a year later with oral involvement revealing Wickham striae on the buccal mucosa and erosions on the upper palate that resolved after 2 months of treatment with cyclosporine oral solution mixed with a 5-times-daily nystatin swish-and-spit (Figure 3). The CLP did not recur but OLP was punctuated by remissions and recurrences on a yearly basis, often related to the cessation of mouthwash and topical creams. The OLP and vulvar lichen planus were successfully treated with as-needed use of a cyclosporine mouthwash swish-and-spit 3 times daily as well as halobetasol ointment 0.05% 3 times daily, respectively. Six years later, the patient was hospitalized for unrelated causes and was lost to follow-up for 2 years.

The patient experienced worsening dysphagia and odynophagia over a period of 2 years (mild dysphagia was first recorded 7 years prior to the initial presentation) and reported an unintentional weight loss of 20 pounds. An endoscopy was performed 3 years after the initial report of dysphagia and noted esophageal erosions (Figure 4A) and a stricture (Figure 4B), but all abnormal involvement was attributed to active gastroesophageal reflux disease. She underwent 8 esophageal dilations to treat the stricture but noted that the duration of symptomatic relief decreased with every subsequent dilation. An esophageal stent was placed 4 years after the initial concern of dysphagia, but it was not well tolerated and had to be removed soon thereafter. A year later, the patient underwent an esophageal bypass with a substernal gastric conduit that provided relief for 2 months but failed to permanently resolve the condition. In fact, her condition worsened over the next 1.5 years when she presented with extreme emaciation attributed to a low appetite and pain while eating. A review of the slides from a prior hospital esophageal biopsy revealed lichen planus (Figure 5). She was prescribed tofacitinib 5 mg BID as a dual-purpose treatment for the rheumatoid arthritis and OLP/ELP. At 1-month follow-up she noted that she had only taken one 5-mg pill daily without notable improvement, and after the visit she started the initial recommendation of 5 mg BID. Over the next several months, her condition continued to consistently improve; the odynophagia resolved, and she regained the majority of her lost weight. Tofacitinib was well tolerated across the course of treatment, and no adverse side effects were noted. Furthermore, the patient regained a full range of motion in the previously immobile arthritic right shoulder. She has experienced no recurrence of the genital lichen planus, OLP, or CLP since starting tofacitinib. To date, the patient is still taking only tofacitinib 5 mg BID with no recurrence of the cutaneous, mucosal, or esophageal lichen planus and has experienced no adverse events from the medication.

Clinical Presentation—Lichen planus—CLP and OLP—most frequently presents between the ages of 40 and 60 years, with a slight female predilection.^1,2 The lesions typically present with the 5 P’s—purple, pruritic, polygonal papules and plaques—with some lesions revealing white lacy lines overlying them called Wickham striae.⁶ The lesions may be red at first before turning purple. They often present on the flexural surfaces of the wrists and ankles as well as the shins and back but rarely affect the face, perhaps because of increased chronic sun exposure.^2,6 Less common locations include the scalp, nails, and mucosal areas (eg, oral, vulvar, conjunctival, laryngeal, esophageal, anal).¹

If CLP is diagnosed, the patient likely will also have oral lesions, which occur in 50% of patients.² Once any form of lichen planus is found, it is important to examine all of the most frequently involved locations—mucocutaneous and cutaneous as well as the nails and scalp. Special care should be taken when examining OLP and genital lichen planus, as long-standing lesions have a 2% to 5% chance of transforming into squamous cell carcinoma.²

Although cases of traditional OLP and CLP are ubiquitous in the literature, ELP rarely is documented because of frequent misdiagnoses. Esophageal lichen planus has a closer histopathologic resemblance to OLP compared to CLP, and its highly variable presentation often results in an inconclusive diagnosis.³ A review of 27 patients with lichen planus highlighted the difficult nature of diagnosing ELP; ELP manifested up to 20 years after initial lichen planus diagnosis, and patients underwent an average of 2.5 dilations prior to the successful diagnosis of ELP. Interestingly, 2 patients in the study presented with ELP in isolation, which emphasizes the importance of secondary examination for lichen planus in the presence of esophageal strictures.⁷ The eTable provides common patient demographics and symptoms to more effectively identify ELP.Differential Diagnosis—Because lichen planus can present anywhere on the body, it may be difficult to differentiate it from other skin conditions. Clinical appearance alone often is insufficient for diagnosing lichen planus, and a punch biopsy often is needed.^2,20 Cutaneous lichen planus may resemble eczema, lichen simplex chronicus, pityriasis rosea, prurigo nodularis, and psoriasis, while OLP may resemble bite trauma, leukoplakia, pemphigus, and thrush.²⁰ Dermoscopy of the tissue makes Wickham striae easier to visualize and assists in the diagnosis of lichen planus. Furthermore, thickening of the stratum granulosum, a prevalence of lymphocytes in the dermoepidermal junction, and vacuolar alteration of the stratum basale help to distinguish between lichen planus and other inflammatory dermatoses.²⁰ A diagnosis of lichen planus merits a full-body skin examination—hair, nails, eyes, oral mucosa, and genitalia—to rule out additional involvement.

Esophageal lichen planus most frequently presents as dysphagia, odynophagia, and weight loss, but other symptoms including heartburn, hoarseness, choking, and epigastric pain may suggest esophageal involvement.⁴ Typically, ELP presents in the proximal and/or central esophagus, assisting in the differentiation between ELP and other esophageal conditions.³ Special consideration should be taken when both ELP and gastroesophageal reflux disease are considered in a differential diagnosis, and it is recommended to pair an upper endoscopy with pH monitoring to avoid misdiagnosis.⁸ Screening endoscopies also are helpful, as they assist in identifying the characteristic white webs, skin peeling, skin surface erosion, and strictures of ELP.⁴ Taken together, dermatologists should encourage patients with cutaneous or mucocutaneous lichen planus to undergo an esophagogastroduodenoscopy, especially in the presence of any of ELP’s common symptoms (eTable).

Etiology—Although the exact etiology of lichen planus is not well established, there are several known correlative factors, including hepatitis C; increased stress; dental materials; oral medications, most frequently antihypertensives and nonsteroidal anti-inflammatory drugs; systemic diseases; and tobacco usage.^6,21

Dental materials used in oral treatments such as silver amalgam, gold, cobalt, palladium, chromium, epoxy resins, and dentures can trigger or exacerbate OLP, and patch testing of a patient’s dental materials can help determine if the reaction was caused by the materials.^6,22 The removal of material contributing to lesions often will cause OLP to resolve.²²

It also has been suggested that the presence of thyroid disorders, autoimmune disease, various cancers, hypertension, type 2 diabetes mellitus, hyperlipidemia, oral sedative usage, and/or vitamin D deficiency may be associated with OLP.^21,23 Although OLP patients who were initially deficient in vitamin D demonstrated marked improvement with supplementation, it is unlikely that vitamin D supplements impacted our patient’s presentation of OLP, as she had been consistently taking them for more than 5 years with no change in OLP presentation.²⁴

Pathogenesis—Lichen planus is thought to be a cytotoxic CD8⁺ T cell–mediated autoimmune disease to a virally modified epidermal self-antigen on keratinocytes. The cytotoxic T cells target the modified self-antigens on basal keratinocytes and induce apoptosis.²⁵ The cytokine-mediated lymphocyte homing mechanism is human leukocyte antigen dependent and involves tumor necrosis factor α as well as IFN-γ and IL-1. The latter cytokines lead to upregulation of vascular adhesion molecules on endothelial vessels of subepithelial vascular plexus as well as a cascade of nonspecific mechanisms such as mast cell degranulation and matrix metalloproteinase activation, resulting in increased basement membrane disruption.⁶

Shao et al¹⁹ underscored the role of IFN-γ in CD8⁺ T cell–mediated cytotoxic cellular responses, noting that the Janus kinase (JAK)–signal transducer and activator of transcription pathway may play a key role in the pathogenesis of lichen planus. They proposed using JAK inhibitors for the treatment of lichen planus, specifically tofacitinib, a JAK1/JAK3 inhibitor, and baricitinib, a JAK1/JAK2 inhibitor, as top therapeutic agents for lichen planus (eTable).¹⁹ Tofacitinib has been reported to successfully treat conditions such as psoriasis, psoriatic arthritis, alopecia areata, vitiligo, atopic dermatitis, sarcoidosis, pyoderma gangrenosum, and lichen planopilaris.²⁶ Additionally, the efficacy of tofacitinib has been established in patients with erosive lichen planus; tofacitinib resulted in marked improvement while prednisone, acitretin, methotrexate, mycophenolate mofetil, and cyclosporine treatment failed.²⁷ Although more studies on tofacitinib’s long-term efficacy, cost, and safety are necessary, tofacitinib may soon play an integral role in the battle against inflammatory dermatoses.

Conclusion

Esophageal lichen planus is an underreported form of lichen planus that often is misdiagnosed. It frequently causes dysphagia and odynophagia, resulting in a major decrease in a patient’s quality of life. We present the case of an 89-year-old woman who underwent procedures to dilate her esophagus that worsened her condition. We emphasize the importance of considering ELP in the differential diagnosis of patients presenting with lichen planus in another region. In our patient, tofacitinib 5 mg BID resolved her condition without any adverse effects.

The Diagnosis: Plasmablastic Lymphoma

A punch biopsy of one of the leg nodules with hematoxylin and eosin staining revealed sheets of medium to large cells with plasmacytic differentiation (Figure, A and B). Immunohistochemistry showed CD79, epithelial membrane antigen, multiple myeloma 1, and CD138 positivity, as well as CD-19 negativity and positive staining on Epstein-Barr virus (EBV) in situ hybridization (Figure, C). Ki-67 stained greater than 90% of the neoplastic cells. Neoplastic cells were found to be λ restricted on κ and λ immunohistochemistry. Human herpesvirus 8 (HHV-8), CD3, and CD20 stains were negative. Subsequent fluorescent in situ hybridization was positive for MYC/immunoglobulin heavy chain (MYC/IGH) rearrangement t(8;14), confirming a diagnosis of plasmablastic lymphoma (PBL).

A bone marrow biopsy revealed normocellular bone marrow with trilineage hematopoiesis and no morphologic, immunophenotypic, or fluorescent in situ hybridization evidence of plasmablastic lymphoma or other pathology in the bone marrow. Our patient was started on hyper-CVAD (cyclophosphamide, vincristine, doxorubicin hydrochloride, dexamethasone) chemotherapy and was doing well with plans for a fourth course of chemotherapy. There is no standardized treatment course for cutaneous PBL, though excision with adjunctive chemotherapy treatment commonly has been reported in the literature.¹

Plasmablastic lymphoma is a rare and aggressive diffuse large B-cell lymphoma associated with EBV infection that compromises approximately 2% to 3% of all HIV-related lymphomas.^1,2 It frequently is associated with immunosuppression in patients with HIV or in transplant recipients on immunosuppression; however, it has been reported in immunocompetent individuals such as elderly patients.² Plasmablastic lymphoma most commonly presents on the buccal mucosa but also can affect the gastrointestinal tract and occasionally has cutaneous manifestations.^1,2 Cutaneous manifestations of PBL range from erythematous infiltrated plaques to ulcerated nodules presenting in an array of colors from flesh colored to violaceous.² Primary cutaneous lesions can be seen on the legs, as in our patient.

Histopathologic examination reveals sheets of plasmablasts or large cells with eccentric nuclei and abundant basophilic cytoplasm.¹ Plasmablastic lymphoma frequently is positive for mature B-cell markers such as CD38, CD138, multiple myeloma 1, and B lymphocyte–induced maturation protein 1.^2,3 Uncommonly, PBL expresses paired box protein Pax-5 and CD20 markers.³ Although pathogenesis is poorly understood, it has been speculated that EBV infection is a common pathogenic factor. Epstein-Barr virus positivity has been noted in 60% of cases.²

Plasmablastic lymphoma and other malignant plasma cell processes such as plasmablastic myeloma (PBM) are morphologically similar. Proliferation of plasmablasts with rare plasmacytic cells is common in PBL, while plasmacytic cells are predominant in PBM. MYC rearrangement/ immunoglobulin heavy chain rearrangement t(8;14) was used to differentiate PBL from PBM in our patient; however, more cases of PBM with MYC/IGH rearrangement t(8;14) have been reported, making it an unreliable differentiating factor.⁴ A detailed clinical, pathologic, and genetic survey remains necessary for confirmatory diagnosis of PBL. Compared to other malignant plasma cell processes, PBL more commonly is seen in immunocompromised patients or those with HIV, such as our patient. Additionally, EBV testing is more likely to be positive in patients with PBL, further supporting this diagnosis in our patient.⁴

Presentations of bacillary angiomatosis, Kaposi sarcoma, and cutaneous lymphoma may be clinically similar; therefore, careful immunohistopathologic differentiation is necessary. Kaposi sarcoma is an angioproliferative disorder that develops from HHV-8 infection and commonly is associated with HIV. It presents as painless vascular lesions in a range of colors with typical progression from patch to plaque to nodules, frequently on the lower extremities. Histologically, admixtures of bland spindle cells, slitlike small vessel proliferation, and lymphocytic infiltration are typical. Neoplastic vessels lack basement membrane zones, resulting in microhemorrhages and hemosiderin deposition. Neoplastic vessels label with CD31 and CD34 endothelial markers in addition to HHV-8 antibodies, which is highly specific for Kaposi sarcoma and differentiates it from PBL.⁵

Bacillary angiomatosis is an infectious neovascular proliferation characterized by papular lesions that may resemble the lesions of PBL. Mixed cell infiltration in inflammatory cells with clumping of granular material is characteristic. Under Warthin-Starry staining, the granular material is abundant in gram-negative rods representing Bartonella species, which is the implicated infectious agent in bacillary angiomatosis.

Lymphomatoid papulosis (LyP) is the most common CD30+ lymphoproliferative disorder and also may present with exophytic nodules. The etiology of LyP remains unknown, but it is suspected that overexpression of CD30 plays a role. Lymphomatoid papulosis presents as red-violaceous papules and nodules in various stages of healing. Although variable histology among types of LyP exists, CD30+ T-cell lymphocytes remain the hallmark of LyP. Type A LyP, which accounts for 80% of LyP cases, reveals CD4+ and CD30+ cells scattered among neutrophils, eosinophils, and small lymphocytes.5 Lymphomatoid papulosis typically is self-healing, recurrent, and carries an excellent prognosis.

Plasmablastic lymphoma remains a rare and aggressive type of diffuse large B-cell lymphoma that can have primary cutaneous manifestations. It is prudent to consider PBL in the differential diagnosis of nodular lower extremity lesions, especially in immunosuppressed patients.

The Diagnosis: Plasmablastic Lymphoma

A punch biopsy of one of the leg nodules with hematoxylin and eosin staining revealed sheets of medium to large cells with plasmacytic differentiation (Figure, A and B). Immunohistochemistry showed CD79, epithelial membrane antigen, multiple myeloma 1, and CD138 positivity, as well as CD-19 negativity and positive staining on Epstein-Barr virus (EBV) in situ hybridization (Figure, C). Ki-67 stained greater than 90% of the neoplastic cells. Neoplastic cells were found to be λ restricted on κ and λ immunohistochemistry. Human herpesvirus 8 (HHV-8), CD3, and CD20 stains were negative. Subsequent fluorescent in situ hybridization was positive for MYC/immunoglobulin heavy chain (MYC/IGH) rearrangement t(8;14), confirming a diagnosis of plasmablastic lymphoma (PBL).

A bone marrow biopsy revealed normocellular bone marrow with trilineage hematopoiesis and no morphologic, immunophenotypic, or fluorescent in situ hybridization evidence of plasmablastic lymphoma or other pathology in the bone marrow. Our patient was started on hyper-CVAD (cyclophosphamide, vincristine, doxorubicin hydrochloride, dexamethasone) chemotherapy and was doing well with plans for a fourth course of chemotherapy. There is no standardized treatment course for cutaneous PBL, though excision with adjunctive chemotherapy treatment commonly has been reported in the literature.¹

Plasmablastic lymphoma is a rare and aggressive diffuse large B-cell lymphoma associated with EBV infection that compromises approximately 2% to 3% of all HIV-related lymphomas.^1,2 It frequently is associated with immunosuppression in patients with HIV or in transplant recipients on immunosuppression; however, it has been reported in immunocompetent individuals such as elderly patients.² Plasmablastic lymphoma most commonly presents on the buccal mucosa but also can affect the gastrointestinal tract and occasionally has cutaneous manifestations.^1,2 Cutaneous manifestations of PBL range from erythematous infiltrated plaques to ulcerated nodules presenting in an array of colors from flesh colored to violaceous.² Primary cutaneous lesions can be seen on the legs, as in our patient.

Histopathologic examination reveals sheets of plasmablasts or large cells with eccentric nuclei and abundant basophilic cytoplasm.¹ Plasmablastic lymphoma frequently is positive for mature B-cell markers such as CD38, CD138, multiple myeloma 1, and B lymphocyte–induced maturation protein 1.^2,3 Uncommonly, PBL expresses paired box protein Pax-5 and CD20 markers.³ Although pathogenesis is poorly understood, it has been speculated that EBV infection is a common pathogenic factor. Epstein-Barr virus positivity has been noted in 60% of cases.²

Plasmablastic lymphoma and other malignant plasma cell processes such as plasmablastic myeloma (PBM) are morphologically similar. Proliferation of plasmablasts with rare plasmacytic cells is common in PBL, while plasmacytic cells are predominant in PBM. MYC rearrangement/ immunoglobulin heavy chain rearrangement t(8;14) was used to differentiate PBL from PBM in our patient; however, more cases of PBM with MYC/IGH rearrangement t(8;14) have been reported, making it an unreliable differentiating factor.⁴ A detailed clinical, pathologic, and genetic survey remains necessary for confirmatory diagnosis of PBL. Compared to other malignant plasma cell processes, PBL more commonly is seen in immunocompromised patients or those with HIV, such as our patient. Additionally, EBV testing is more likely to be positive in patients with PBL, further supporting this diagnosis in our patient.⁴

Presentations of bacillary angiomatosis, Kaposi sarcoma, and cutaneous lymphoma may be clinically similar; therefore, careful immunohistopathologic differentiation is necessary. Kaposi sarcoma is an angioproliferative disorder that develops from HHV-8 infection and commonly is associated with HIV. It presents as painless vascular lesions in a range of colors with typical progression from patch to plaque to nodules, frequently on the lower extremities. Histologically, admixtures of bland spindle cells, slitlike small vessel proliferation, and lymphocytic infiltration are typical. Neoplastic vessels lack basement membrane zones, resulting in microhemorrhages and hemosiderin deposition. Neoplastic vessels label with CD31 and CD34 endothelial markers in addition to HHV-8 antibodies, which is highly specific for Kaposi sarcoma and differentiates it from PBL.⁵

Bacillary angiomatosis is an infectious neovascular proliferation characterized by papular lesions that may resemble the lesions of PBL. Mixed cell infiltration in inflammatory cells with clumping of granular material is characteristic. Under Warthin-Starry staining, the granular material is abundant in gram-negative rods representing Bartonella species, which is the implicated infectious agent in bacillary angiomatosis.

Lymphomatoid papulosis (LyP) is the most common CD30+ lymphoproliferative disorder and also may present with exophytic nodules. The etiology of LyP remains unknown, but it is suspected that overexpression of CD30 plays a role. Lymphomatoid papulosis presents as red-violaceous papules and nodules in various stages of healing. Although variable histology among types of LyP exists, CD30+ T-cell lymphocytes remain the hallmark of LyP. Type A LyP, which accounts for 80% of LyP cases, reveals CD4+ and CD30+ cells scattered among neutrophils, eosinophils, and small lymphocytes.5 Lymphomatoid papulosis typically is self-healing, recurrent, and carries an excellent prognosis.

Plasmablastic lymphoma remains a rare and aggressive type of diffuse large B-cell lymphoma that can have primary cutaneous manifestations. It is prudent to consider PBL in the differential diagnosis of nodular lower extremity lesions, especially in immunosuppressed patients.

The Diagnosis: Plasmablastic Lymphoma

A punch biopsy of one of the leg nodules with hematoxylin and eosin staining revealed sheets of medium to large cells with plasmacytic differentiation (Figure, A and B). Immunohistochemistry showed CD79, epithelial membrane antigen, multiple myeloma 1, and CD138 positivity, as well as CD-19 negativity and positive staining on Epstein-Barr virus (EBV) in situ hybridization (Figure, C). Ki-67 stained greater than 90% of the neoplastic cells. Neoplastic cells were found to be λ restricted on κ and λ immunohistochemistry. Human herpesvirus 8 (HHV-8), CD3, and CD20 stains were negative. Subsequent fluorescent in situ hybridization was positive for MYC/immunoglobulin heavy chain (MYC/IGH) rearrangement t(8;14), confirming a diagnosis of plasmablastic lymphoma (PBL).

A bone marrow biopsy revealed normocellular bone marrow with trilineage hematopoiesis and no morphologic, immunophenotypic, or fluorescent in situ hybridization evidence of plasmablastic lymphoma or other pathology in the bone marrow. Our patient was started on hyper-CVAD (cyclophosphamide, vincristine, doxorubicin hydrochloride, dexamethasone) chemotherapy and was doing well with plans for a fourth course of chemotherapy. There is no standardized treatment course for cutaneous PBL, though excision with adjunctive chemotherapy treatment commonly has been reported in the literature.¹

Plasmablastic lymphoma is a rare and aggressive diffuse large B-cell lymphoma associated with EBV infection that compromises approximately 2% to 3% of all HIV-related lymphomas.^1,2 It frequently is associated with immunosuppression in patients with HIV or in transplant recipients on immunosuppression; however, it has been reported in immunocompetent individuals such as elderly patients.² Plasmablastic lymphoma most commonly presents on the buccal mucosa but also can affect the gastrointestinal tract and occasionally has cutaneous manifestations.^1,2 Cutaneous manifestations of PBL range from erythematous infiltrated plaques to ulcerated nodules presenting in an array of colors from flesh colored to violaceous.² Primary cutaneous lesions can be seen on the legs, as in our patient.

Histopathologic examination reveals sheets of plasmablasts or large cells with eccentric nuclei and abundant basophilic cytoplasm.¹ Plasmablastic lymphoma frequently is positive for mature B-cell markers such as CD38, CD138, multiple myeloma 1, and B lymphocyte–induced maturation protein 1.^2,3 Uncommonly, PBL expresses paired box protein Pax-5 and CD20 markers.³ Although pathogenesis is poorly understood, it has been speculated that EBV infection is a common pathogenic factor. Epstein-Barr virus positivity has been noted in 60% of cases.²

Plasmablastic lymphoma and other malignant plasma cell processes such as plasmablastic myeloma (PBM) are morphologically similar. Proliferation of plasmablasts with rare plasmacytic cells is common in PBL, while plasmacytic cells are predominant in PBM. MYC rearrangement/ immunoglobulin heavy chain rearrangement t(8;14) was used to differentiate PBL from PBM in our patient; however, more cases of PBM with MYC/IGH rearrangement t(8;14) have been reported, making it an unreliable differentiating factor.⁴ A detailed clinical, pathologic, and genetic survey remains necessary for confirmatory diagnosis of PBL. Compared to other malignant plasma cell processes, PBL more commonly is seen in immunocompromised patients or those with HIV, such as our patient. Additionally, EBV testing is more likely to be positive in patients with PBL, further supporting this diagnosis in our patient.⁴

Presentations of bacillary angiomatosis, Kaposi sarcoma, and cutaneous lymphoma may be clinically similar; therefore, careful immunohistopathologic differentiation is necessary. Kaposi sarcoma is an angioproliferative disorder that develops from HHV-8 infection and commonly is associated with HIV. It presents as painless vascular lesions in a range of colors with typical progression from patch to plaque to nodules, frequently on the lower extremities. Histologically, admixtures of bland spindle cells, slitlike small vessel proliferation, and lymphocytic infiltration are typical. Neoplastic vessels lack basement membrane zones, resulting in microhemorrhages and hemosiderin deposition. Neoplastic vessels label with CD31 and CD34 endothelial markers in addition to HHV-8 antibodies, which is highly specific for Kaposi sarcoma and differentiates it from PBL.⁵

Bacillary angiomatosis is an infectious neovascular proliferation characterized by papular lesions that may resemble the lesions of PBL. Mixed cell infiltration in inflammatory cells with clumping of granular material is characteristic. Under Warthin-Starry staining, the granular material is abundant in gram-negative rods representing Bartonella species, which is the implicated infectious agent in bacillary angiomatosis.

Lymphomatoid papulosis (LyP) is the most common CD30+ lymphoproliferative disorder and also may present with exophytic nodules. The etiology of LyP remains unknown, but it is suspected that overexpression of CD30 plays a role. Lymphomatoid papulosis presents as red-violaceous papules and nodules in various stages of healing. Although variable histology among types of LyP exists, CD30+ T-cell lymphocytes remain the hallmark of LyP. Type A LyP, which accounts for 80% of LyP cases, reveals CD4+ and CD30+ cells scattered among neutrophils, eosinophils, and small lymphocytes.5 Lymphomatoid papulosis typically is self-healing, recurrent, and carries an excellent prognosis.

Plasmablastic lymphoma remains a rare and aggressive type of diffuse large B-cell lymphoma that can have primary cutaneous manifestations. It is prudent to consider PBL in the differential diagnosis of nodular lower extremity lesions, especially in immunosuppressed patients.

SAN DIEGO – Today’s molecular tests for managing melanoma patients are used to reclassify melanoma, identify patients at risk, as well as for diagnosis, prognosis, and treatment, but each one has its specific applications, benefits, and drawbacks, according to Gregory A. Hosler, MD, PhD.

At the annual Cutaneous Malignancy Update, Dr. Hosler, director of dermatopathology for ProPath, highlighted the following molecular tests currently used for the diagnosis of challenging melanocytic lesions:

Comparative genomic hybridization (CGH). This technique allows for the detection of chromosomal copy number changes throughout the tumor genome. “With CGH, test (tumor) DNA and normal DNA are differentially labeled and compared to a reference library. Gains and losses of portions of the tumor genome are determined by comparing the relative signals from these two groups,” said Dr. Hosler, clinical professor of pathology and dermatology at the University of Texas Southwestern Medical Center, Dallas.

“In the past, your library was a metaphase of spread of chromosomes, which introduced technical challenges and made performance of the assay labor intensive. Because of this, CGH is not routinely performed by clinical laboratories and is used more as an exploratory/research technique.”

Array CGH (also known as SNP array). Newer versions of CGH use short DNA sequences that are tiled onto a chip. “The interesting thing about these chips is that you can purchase them or design them on your own,” Dr. Hosler said. “The chips may cover the entire genome or cover specific areas of the genome at higher resolution.” One upside of array CGH, he continued, is that it allows one to detect essentially all gains or losses of chromosomal material in a single reaction. “It is not subject to the artifacts associated with cutting thin sections like with fluorescence in situ hybridization (FISH); it can detect copy number neutral loss of heterozygosity, and it is more scalable,” Dr. Hosler said at the meeting, which was hosted by Scripps MD Anderson Cancer Center.

One downside of array CGH is that does not allow one to analyze specific cells, “so if you have a tumor that’s heterogeneous, the assay is agnostic to this and spits out a result based on all the material provided,” he said. “You can’t parse out different areas of the lesion. It also does not track balanced translocations.” In addition, he said, “there are also questions about reimbursement and these are lab-developed tests, so each lab’s assay is different. Finally, it requires specialized equipment and expertise for interpretation.”

FISH. First-generation melanoma FISH assays, which became available in 2009, used six probes and four colors and had a sensitivity of about 87% and specificity of about 95%, Dr. Hosler said, but there were problems with those assays, particularly related to Spitz nevi. Spitz nevi often duplicate their chromosomes, “so instead of being diploid they’re tetraploid,” he said.

“The second-generation melanoma FISH assays addressed this by adding centromeres to the assay, and targeted probes could be compared to the centromeres on the same chromosome to determine if these were true copy number gains, due to genetic instability, or gains or losses of entire arms or whole chromosomes. This modification and the addition of new targets really improved upon the sensitivity and specificity (94% and 98%, respectively),” he said, noting that this assay is widely used.

Upsides of melanoma FISH assays are that they are a “fairly routine methodology” in large clinical laboratories, he said, and that many labs are familiar with interpretation. “I would say the biggest advantage to FISH is its ability to analyze specific cells, which is useful with small or heterogeneous tumors,” Dr. Hosler said. “Also, there is a genetic reimbursement code for it, and it yields diagnostic and potentially prognostic information.” For example, certain copy number changes have shown to portend a worse prognosis if they’re present in a melanocytic tumor, including alterations in CDKN2A, CCND1, MYC, topoisomerase, and BAP1.

Downsides of melanoma FISH assays are that they are expensive, labor-intensive, and require experts to interpret the results. “The stacking and truncation of cell nuclei innate to paraffin-embedded FISH make interpretation difficult,” he said. “Also, all colors cannot be viewed simultaneously, and each lab’s assay potentially is different, requiring validation. These are not [Food and Drug Administration]-approved tests.”

Next generation sequencing (NGS). Also known as high-throughput sequencing, this technique allows for the generation of millions of sequencing reads that are aligned to a standard human genome, and likely represents the wave of the future. “With NGS you can increase breadth, so you can sequence the entire genome if you want, but you can also increase depth, meaning increasing the number of reads over a single target of the genome,” Dr. Hosler said. “That’s useful if you’re looking for a low frequency mutation.”

For example, NGS allows one to detect alterations of BRAF and KIT and other potentially actionable alterations. It can also be used to detect mutations in benign and malignant melanocytic lesions, including historically diagnostically challenging Spitz and desmoplastic subgroups. Several different NGS technologies exist, and there are different strategies behind each assay, including whole genome sequencing, whole exome sequencing, transcriptome sequencing, and targeted panels. “I’ve seen panels of 10 and I’ve seen panels of 1,500; there’s a wide range,” Dr. Hosler said. “The biggest challenge with NGS, currently, is that it’s difficult to interpret. Trying to figure out what’s important and what’s not important can be challenging. Often you need a team of people who are experts in bioinformatics to interpret these results.”

Slow turnaround time is another downside. “It can take a month to get results, and sometimes clinicians don’t want to wait that long, especially if they think a lesion is melanoma, so that’s an area of focus for NGS laboratories,” he said. “And there are questions on reimbursement. If you run NGS on every unusual melanocytic lesion, that’s not a good use of health care dollars. Who’s paying for it? I don’t have an answer for you. It’s all over the map right now. Each lab’s test and billing practice is different.”

Dr. Hosler reported having no relevant financial disclosures. ProPath is a nationwide pathology practice.

SAN DIEGO – Today’s molecular tests for managing melanoma patients are used to reclassify melanoma, identify patients at risk, as well as for diagnosis, prognosis, and treatment, but each one has its specific applications, benefits, and drawbacks, according to Gregory A. Hosler, MD, PhD.

At the annual Cutaneous Malignancy Update, Dr. Hosler, director of dermatopathology for ProPath, highlighted the following molecular tests currently used for the diagnosis of challenging melanocytic lesions:

Comparative genomic hybridization (CGH). This technique allows for the detection of chromosomal copy number changes throughout the tumor genome. “With CGH, test (tumor) DNA and normal DNA are differentially labeled and compared to a reference library. Gains and losses of portions of the tumor genome are determined by comparing the relative signals from these two groups,” said Dr. Hosler, clinical professor of pathology and dermatology at the University of Texas Southwestern Medical Center, Dallas.

“In the past, your library was a metaphase of spread of chromosomes, which introduced technical challenges and made performance of the assay labor intensive. Because of this, CGH is not routinely performed by clinical laboratories and is used more as an exploratory/research technique.”

Array CGH (also known as SNP array). Newer versions of CGH use short DNA sequences that are tiled onto a chip. “The interesting thing about these chips is that you can purchase them or design them on your own,” Dr. Hosler said. “The chips may cover the entire genome or cover specific areas of the genome at higher resolution.” One upside of array CGH, he continued, is that it allows one to detect essentially all gains or losses of chromosomal material in a single reaction. “It is not subject to the artifacts associated with cutting thin sections like with fluorescence in situ hybridization (FISH); it can detect copy number neutral loss of heterozygosity, and it is more scalable,” Dr. Hosler said at the meeting, which was hosted by Scripps MD Anderson Cancer Center.

One downside of array CGH is that does not allow one to analyze specific cells, “so if you have a tumor that’s heterogeneous, the assay is agnostic to this and spits out a result based on all the material provided,” he said. “You can’t parse out different areas of the lesion. It also does not track balanced translocations.” In addition, he said, “there are also questions about reimbursement and these are lab-developed tests, so each lab’s assay is different. Finally, it requires specialized equipment and expertise for interpretation.”

FISH. First-generation melanoma FISH assays, which became available in 2009, used six probes and four colors and had a sensitivity of about 87% and specificity of about 95%, Dr. Hosler said, but there were problems with those assays, particularly related to Spitz nevi. Spitz nevi often duplicate their chromosomes, “so instead of being diploid they’re tetraploid,” he said.

“The second-generation melanoma FISH assays addressed this by adding centromeres to the assay, and targeted probes could be compared to the centromeres on the same chromosome to determine if these were true copy number gains, due to genetic instability, or gains or losses of entire arms or whole chromosomes. This modification and the addition of new targets really improved upon the sensitivity and specificity (94% and 98%, respectively),” he said, noting that this assay is widely used.

Upsides of melanoma FISH assays are that they are a “fairly routine methodology” in large clinical laboratories, he said, and that many labs are familiar with interpretation. “I would say the biggest advantage to FISH is its ability to analyze specific cells, which is useful with small or heterogeneous tumors,” Dr. Hosler said. “Also, there is a genetic reimbursement code for it, and it yields diagnostic and potentially prognostic information.” For example, certain copy number changes have shown to portend a worse prognosis if they’re present in a melanocytic tumor, including alterations in CDKN2A, CCND1, MYC, topoisomerase, and BAP1.

Downsides of melanoma FISH assays are that they are expensive, labor-intensive, and require experts to interpret the results. “The stacking and truncation of cell nuclei innate to paraffin-embedded FISH make interpretation difficult,” he said. “Also, all colors cannot be viewed simultaneously, and each lab’s assay potentially is different, requiring validation. These are not [Food and Drug Administration]-approved tests.”

Next generation sequencing (NGS). Also known as high-throughput sequencing, this technique allows for the generation of millions of sequencing reads that are aligned to a standard human genome, and likely represents the wave of the future. “With NGS you can increase breadth, so you can sequence the entire genome if you want, but you can also increase depth, meaning increasing the number of reads over a single target of the genome,” Dr. Hosler said. “That’s useful if you’re looking for a low frequency mutation.”

For example, NGS allows one to detect alterations of BRAF and KIT and other potentially actionable alterations. It can also be used to detect mutations in benign and malignant melanocytic lesions, including historically diagnostically challenging Spitz and desmoplastic subgroups. Several different NGS technologies exist, and there are different strategies behind each assay, including whole genome sequencing, whole exome sequencing, transcriptome sequencing, and targeted panels. “I’ve seen panels of 10 and I’ve seen panels of 1,500; there’s a wide range,” Dr. Hosler said. “The biggest challenge with NGS, currently, is that it’s difficult to interpret. Trying to figure out what’s important and what’s not important can be challenging. Often you need a team of people who are experts in bioinformatics to interpret these results.”

Slow turnaround time is another downside. “It can take a month to get results, and sometimes clinicians don’t want to wait that long, especially if they think a lesion is melanoma, so that’s an area of focus for NGS laboratories,” he said. “And there are questions on reimbursement. If you run NGS on every unusual melanocytic lesion, that’s not a good use of health care dollars. Who’s paying for it? I don’t have an answer for you. It’s all over the map right now. Each lab’s test and billing practice is different.”

Dr. Hosler reported having no relevant financial disclosures. ProPath is a nationwide pathology practice.

SAN DIEGO – Today’s molecular tests for managing melanoma patients are used to reclassify melanoma, identify patients at risk, as well as for diagnosis, prognosis, and treatment, but each one has its specific applications, benefits, and drawbacks, according to Gregory A. Hosler, MD, PhD.

At the annual Cutaneous Malignancy Update, Dr. Hosler, director of dermatopathology for ProPath, highlighted the following molecular tests currently used for the diagnosis of challenging melanocytic lesions:

Comparative genomic hybridization (CGH). This technique allows for the detection of chromosomal copy number changes throughout the tumor genome. “With CGH, test (tumor) DNA and normal DNA are differentially labeled and compared to a reference library. Gains and losses of portions of the tumor genome are determined by comparing the relative signals from these two groups,” said Dr. Hosler, clinical professor of pathology and dermatology at the University of Texas Southwestern Medical Center, Dallas.

“In the past, your library was a metaphase of spread of chromosomes, which introduced technical challenges and made performance of the assay labor intensive. Because of this, CGH is not routinely performed by clinical laboratories and is used more as an exploratory/research technique.”

Array CGH (also known as SNP array). Newer versions of CGH use short DNA sequences that are tiled onto a chip. “The interesting thing about these chips is that you can purchase them or design them on your own,” Dr. Hosler said. “The chips may cover the entire genome or cover specific areas of the genome at higher resolution.” One upside of array CGH, he continued, is that it allows one to detect essentially all gains or losses of chromosomal material in a single reaction. “It is not subject to the artifacts associated with cutting thin sections like with fluorescence in situ hybridization (FISH); it can detect copy number neutral loss of heterozygosity, and it is more scalable,” Dr. Hosler said at the meeting, which was hosted by Scripps MD Anderson Cancer Center.

One downside of array CGH is that does not allow one to analyze specific cells, “so if you have a tumor that’s heterogeneous, the assay is agnostic to this and spits out a result based on all the material provided,” he said. “You can’t parse out different areas of the lesion. It also does not track balanced translocations.” In addition, he said, “there are also questions about reimbursement and these are lab-developed tests, so each lab’s assay is different. Finally, it requires specialized equipment and expertise for interpretation.”

FISH. First-generation melanoma FISH assays, which became available in 2009, used six probes and four colors and had a sensitivity of about 87% and specificity of about 95%, Dr. Hosler said, but there were problems with those assays, particularly related to Spitz nevi. Spitz nevi often duplicate their chromosomes, “so instead of being diploid they’re tetraploid,” he said.

“The second-generation melanoma FISH assays addressed this by adding centromeres to the assay, and targeted probes could be compared to the centromeres on the same chromosome to determine if these were true copy number gains, due to genetic instability, or gains or losses of entire arms or whole chromosomes. This modification and the addition of new targets really improved upon the sensitivity and specificity (94% and 98%, respectively),” he said, noting that this assay is widely used.

Upsides of melanoma FISH assays are that they are a “fairly routine methodology” in large clinical laboratories, he said, and that many labs are familiar with interpretation. “I would say the biggest advantage to FISH is its ability to analyze specific cells, which is useful with small or heterogeneous tumors,” Dr. Hosler said. “Also, there is a genetic reimbursement code for it, and it yields diagnostic and potentially prognostic information.” For example, certain copy number changes have shown to portend a worse prognosis if they’re present in a melanocytic tumor, including alterations in CDKN2A, CCND1, MYC, topoisomerase, and BAP1.

Downsides of melanoma FISH assays are that they are expensive, labor-intensive, and require experts to interpret the results. “The stacking and truncation of cell nuclei innate to paraffin-embedded FISH make interpretation difficult,” he said. “Also, all colors cannot be viewed simultaneously, and each lab’s assay potentially is different, requiring validation. These are not [Food and Drug Administration]-approved tests.”

Next generation sequencing (NGS). Also known as high-throughput sequencing, this technique allows for the generation of millions of sequencing reads that are aligned to a standard human genome, and likely represents the wave of the future. “With NGS you can increase breadth, so you can sequence the entire genome if you want, but you can also increase depth, meaning increasing the number of reads over a single target of the genome,” Dr. Hosler said. “That’s useful if you’re looking for a low frequency mutation.”

For example, NGS allows one to detect alterations of BRAF and KIT and other potentially actionable alterations. It can also be used to detect mutations in benign and malignant melanocytic lesions, including historically diagnostically challenging Spitz and desmoplastic subgroups. Several different NGS technologies exist, and there are different strategies behind each assay, including whole genome sequencing, whole exome sequencing, transcriptome sequencing, and targeted panels. “I’ve seen panels of 10 and I’ve seen panels of 1,500; there’s a wide range,” Dr. Hosler said. “The biggest challenge with NGS, currently, is that it’s difficult to interpret. Trying to figure out what’s important and what’s not important can be challenging. Often you need a team of people who are experts in bioinformatics to interpret these results.”

Slow turnaround time is another downside. “It can take a month to get results, and sometimes clinicians don’t want to wait that long, especially if they think a lesion is melanoma, so that’s an area of focus for NGS laboratories,” he said. “And there are questions on reimbursement. If you run NGS on every unusual melanocytic lesion, that’s not a good use of health care dollars. Who’s paying for it? I don’t have an answer for you. It’s all over the map right now. Each lab’s test and billing practice is different.”

Dr. Hosler reported having no relevant financial disclosures. ProPath is a nationwide pathology practice.

The Diagnosis: Aneurysmal Dermatofibroma

A shave biopsy of the entire tumor was performed at the initial visit. Histologic examination with hematoxylin and eosin staining revealed a fibrohistiocytic infiltrate containing cleftlike cavernous spaces lined by epithelial cells (Figure, A). Immunohistochemical staining revealed factor XIIIa expression on fibrohistiocytic cells (Figure, B). CD34 was expressed on vascular endothelial cells, but it failed to highlight the fibrohistiocytic space (Figure, C). Overall, these findings supported the diagnosis of aneurysmal dermatofibroma. The lesion healed without complications, and the patient was counseled on the risk for recurrence. He was offered localized excision but opted for conservative management without excision and close follow-up and monitoring.

Dermatofibromas are common benign cutaneous nodules that often are asymptomatic and occur on the extremities. Dermatofibromas also are known as cutaneous fibrous histiocytomas and have numerous histologic variants. Aneurysmal dermatofibroma (also called aneurysmal fibrous histiocytoma) is a rare histologic variant of dermatofibroma presenting as a slow-growing exophytic tumor that can be purple, red, brown, or blue. Although classic dermatofibromas typically constitute a straightforward diagnosis, aneurysmal dermatofibromas often are more challenging to clinically differentiate from other cutaneous neoplasms. Additionally, due to the exophytic nature and larger size (0.5–4.0 cm), aneurysmal dermatofibromas do not exhibit the characteristic dimple (Fitzpatrick) sign found in many dermatofibromas. Aneurysmal dermatofibromas are 10 times more likely to recur than classic dermatofibromas.^1-4

Aneurysmal dermatofibromas can mimic other cutaneous neoplasms, some indolent and others more aggressive. Similar to aneurysmal dermatofibromas, solitary neurofibromas and nevi lipomatosus can appear as asymptomatic exophytic nodules with a similar spectrum of color and indolent clinical courses. In nevus lipomatosus, the dermis is almost entirely replaced by mature adipose tissue.⁵ Solitary neurofibromas represent a proliferation of neuromesenchymal cells with haphazardly arranged, wavy nuclei characteristic of nerve cells.⁶ Dermatofibrosarcoma protuberans can be distinguished from aneurysmal dermatofibroma by lack of factor XIIIa expression and diffuse positivity for CD34.⁷ Finally, aneurysmal dermatofibromas may resemble vascular tumors such as nodular Kaposi sarcoma. Kaposi sarcoma can be differentiated from an aneurysmal dermatofibroma by the presence of characteristic vascular wrapping, the absence of fibrohistiocytic cells, and expression of human herpesvirus 8 latent nuclear antigen-1.^1,8 Although aneurysmal dermatofibromas are of low malignant potential, they are associated with a higher rate of recurrence compared to common dermatofibromas.⁹ Definitive treatment involves complete excision with follow-up to ensure no signs of recurrence.¹⁰ Incomplete excision can increase the likelihood of recurrence, especially for larger aneurysmal dermatofibromas. Aneurysmal dermatofibromas are one of the subtypes of dermatofibromas that may extend into the subcutaneous tissue. Han et al² found that 77.8% of aneurysmal dermatofibromas extended into subcutaneous tissue. Recognizing the clinical and pathological features of this rare subtype of dermatofibroma can aid dermatologists in appropriate recognition and management.

The Diagnosis: Aneurysmal Dermatofibroma

A shave biopsy of the entire tumor was performed at the initial visit. Histologic examination with hematoxylin and eosin staining revealed a fibrohistiocytic infiltrate containing cleftlike cavernous spaces lined by epithelial cells (Figure, A). Immunohistochemical staining revealed factor XIIIa expression on fibrohistiocytic cells (Figure, B). CD34 was expressed on vascular endothelial cells, but it failed to highlight the fibrohistiocytic space (Figure, C). Overall, these findings supported the diagnosis of aneurysmal dermatofibroma. The lesion healed without complications, and the patient was counseled on the risk for recurrence. He was offered localized excision but opted for conservative management without excision and close follow-up and monitoring.

Dermatofibromas are common benign cutaneous nodules that often are asymptomatic and occur on the extremities. Dermatofibromas also are known as cutaneous fibrous histiocytomas and have numerous histologic variants. Aneurysmal dermatofibroma (also called aneurysmal fibrous histiocytoma) is a rare histologic variant of dermatofibroma presenting as a slow-growing exophytic tumor that can be purple, red, brown, or blue. Although classic dermatofibromas typically constitute a straightforward diagnosis, aneurysmal dermatofibromas often are more challenging to clinically differentiate from other cutaneous neoplasms. Additionally, due to the exophytic nature and larger size (0.5–4.0 cm), aneurysmal dermatofibromas do not exhibit the characteristic dimple (Fitzpatrick) sign found in many dermatofibromas. Aneurysmal dermatofibromas are 10 times more likely to recur than classic dermatofibromas.^1-4

Aneurysmal dermatofibromas can mimic other cutaneous neoplasms, some indolent and others more aggressive. Similar to aneurysmal dermatofibromas, solitary neurofibromas and nevi lipomatosus can appear as asymptomatic exophytic nodules with a similar spectrum of color and indolent clinical courses. In nevus lipomatosus, the dermis is almost entirely replaced by mature adipose tissue.⁵ Solitary neurofibromas represent a proliferation of neuromesenchymal cells with haphazardly arranged, wavy nuclei characteristic of nerve cells.⁶ Dermatofibrosarcoma protuberans can be distinguished from aneurysmal dermatofibroma by lack of factor XIIIa expression and diffuse positivity for CD34.⁷ Finally, aneurysmal dermatofibromas may resemble vascular tumors such as nodular Kaposi sarcoma. Kaposi sarcoma can be differentiated from an aneurysmal dermatofibroma by the presence of characteristic vascular wrapping, the absence of fibrohistiocytic cells, and expression of human herpesvirus 8 latent nuclear antigen-1.^1,8 Although aneurysmal dermatofibromas are of low malignant potential, they are associated with a higher rate of recurrence compared to common dermatofibromas.⁹ Definitive treatment involves complete excision with follow-up to ensure no signs of recurrence.¹⁰ Incomplete excision can increase the likelihood of recurrence, especially for larger aneurysmal dermatofibromas. Aneurysmal dermatofibromas are one of the subtypes of dermatofibromas that may extend into the subcutaneous tissue. Han et al² found that 77.8% of aneurysmal dermatofibromas extended into subcutaneous tissue. Recognizing the clinical and pathological features of this rare subtype of dermatofibroma can aid dermatologists in appropriate recognition and management.

The Diagnosis: Aneurysmal Dermatofibroma

A shave biopsy of the entire tumor was performed at the initial visit. Histologic examination with hematoxylin and eosin staining revealed a fibrohistiocytic infiltrate containing cleftlike cavernous spaces lined by epithelial cells (Figure, A). Immunohistochemical staining revealed factor XIIIa expression on fibrohistiocytic cells (Figure, B). CD34 was expressed on vascular endothelial cells, but it failed to highlight the fibrohistiocytic space (Figure, C). Overall, these findings supported the diagnosis of aneurysmal dermatofibroma. The lesion healed without complications, and the patient was counseled on the risk for recurrence. He was offered localized excision but opted for conservative management without excision and close follow-up and monitoring.

Dermatofibromas are common benign cutaneous nodules that often are asymptomatic and occur on the extremities. Dermatofibromas also are known as cutaneous fibrous histiocytomas and have numerous histologic variants. Aneurysmal dermatofibroma (also called aneurysmal fibrous histiocytoma) is a rare histologic variant of dermatofibroma presenting as a slow-growing exophytic tumor that can be purple, red, brown, or blue. Although classic dermatofibromas typically constitute a straightforward diagnosis, aneurysmal dermatofibromas often are more challenging to clinically differentiate from other cutaneous neoplasms. Additionally, due to the exophytic nature and larger size (0.5–4.0 cm), aneurysmal dermatofibromas do not exhibit the characteristic dimple (Fitzpatrick) sign found in many dermatofibromas. Aneurysmal dermatofibromas are 10 times more likely to recur than classic dermatofibromas.^1-4

Aneurysmal dermatofibromas can mimic other cutaneous neoplasms, some indolent and others more aggressive. Similar to aneurysmal dermatofibromas, solitary neurofibromas and nevi lipomatosus can appear as asymptomatic exophytic nodules with a similar spectrum of color and indolent clinical courses. In nevus lipomatosus, the dermis is almost entirely replaced by mature adipose tissue.⁵ Solitary neurofibromas represent a proliferation of neuromesenchymal cells with haphazardly arranged, wavy nuclei characteristic of nerve cells.⁶ Dermatofibrosarcoma protuberans can be distinguished from aneurysmal dermatofibroma by lack of factor XIIIa expression and diffuse positivity for CD34.⁷ Finally, aneurysmal dermatofibromas may resemble vascular tumors such as nodular Kaposi sarcoma. Kaposi sarcoma can be differentiated from an aneurysmal dermatofibroma by the presence of characteristic vascular wrapping, the absence of fibrohistiocytic cells, and expression of human herpesvirus 8 latent nuclear antigen-1.^1,8 Although aneurysmal dermatofibromas are of low malignant potential, they are associated with a higher rate of recurrence compared to common dermatofibromas.⁹ Definitive treatment involves complete excision with follow-up to ensure no signs of recurrence.¹⁰ Incomplete excision can increase the likelihood of recurrence, especially for larger aneurysmal dermatofibromas. Aneurysmal dermatofibromas are one of the subtypes of dermatofibromas that may extend into the subcutaneous tissue. Han et al² found that 77.8% of aneurysmal dermatofibromas extended into subcutaneous tissue. Recognizing the clinical and pathological features of this rare subtype of dermatofibroma can aid dermatologists in appropriate recognition and management.

The patient was diagnosed with lichen nitidus, given the characteristic clinical presentation.

Lichen nitidus is a rare chronic inflammatory condition of the skin that most commonly presents in children and young adults and does not seem to be restricted to any sex or race. The classic lesions are described as asymptomatic to slightly pruritic, small (1 mm), skin-colored to hypopigmented flat-topped papules.

Koebner phenomenon is usually seen in which the skin lesions appear in areas of traumatized healthy skin. The extremities, abdomen, chest, and penis are common locations for the lesions to occur. Rarely, the oral mucosa or nails can be involved. It has been described in patients with a diagnosis of Crohn’s disease, Niemann-Pick disease, Down syndrome, and HIV. The rare, generalized purpuric variant has been reported in a few cases associated with interferon and ribavirin treatment for hepatitis C infection and nivolumab treatment for cancer. The pathophysiology of lichen nitidus is unknown.

Lichen nitidus can occur in the presence of other skin conditions like lichen planus, atopic dermatitis, vitiligo, erythema nodosum, and lichen spinulosus. Histopathologic characteristics of lichen nitidus are described as a “ball and claw” of epidermal rete around a lymphohistiocytic infiltrate. Parakeratosis overlying epidermal atrophy and focal basal liquefaction degeneration is also seen.

The differential diagnosis of lichen nitidus includes flat warts, which can present as clusters of small flat-topped papules that can show a pseudo-Koebner phenomenon (where the virus is seeded in traumatized skin). The morphological difference between the condition is that lichen nitidus lesions are usually monomorphic, compared with flat warts, which usually present with different sizes and shapes.

Patients with a history of allergic contact dermatitis may present with a generalized monomorphic eruption of skin-colored papules (known as ID reaction) that can sometimes be very similar to lichen nitidus. Allergic contact dermatitis tends to respond fairly quickly to topical or systemic corticosteroids, unlike lichen nitidus. There are a few reports that consider lichen nitidus to be a variant of lichen planus, although they have different histopathologic findings. Lichen planus lesions are described as polygonal, pruritic, purple to pink papules most commonly seen on the wrists, lower back, and ankles. Lichen planus can be seen in patients with hepatitis C and may also occur secondary to medication.

Milia are small keratin cysts on the skin that are commonly seen in babies as primary milia and can be seen in older children secondary to trauma (commonly on the eyelids) or medications. Given their size and monomorphic appearance, they can sometimes be confused with lichen nitidus.

Lichen nitidus is often asymptomatic and the lesions resolve within a few months to years. Topical corticosteroids can be helpful to alleviate the symptoms in patients who present with pruritus. In more persistent and generalized cases, phototherapy, systemic corticosteroids, acitretin, isotretinoin, or cyclosporine can be considered.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.

References

Chu J and Lam JM. CMAJ. 2014 Dec 9;186(18):E688.

Lestringant G et al. Dermatology 1996;192:171-3.

Peterson JA et al. Proc (Bayl Univ Med Cent). 2021 Aug 25;35(1):70-2.

Schwartz C and Goodman MB. “Lichen nitidus,” in StatPearls. Treasure Island, Fla.: StatPearls Publishing, 2022.

The patient was diagnosed with lichen nitidus, given the characteristic clinical presentation.

Lichen nitidus is a rare chronic inflammatory condition of the skin that most commonly presents in children and young adults and does not seem to be restricted to any sex or race. The classic lesions are described as asymptomatic to slightly pruritic, small (1 mm), skin-colored to hypopigmented flat-topped papules.

Koebner phenomenon is usually seen in which the skin lesions appear in areas of traumatized healthy skin. The extremities, abdomen, chest, and penis are common locations for the lesions to occur. Rarely, the oral mucosa or nails can be involved. It has been described in patients with a diagnosis of Crohn’s disease, Niemann-Pick disease, Down syndrome, and HIV. The rare, generalized purpuric variant has been reported in a few cases associated with interferon and ribavirin treatment for hepatitis C infection and nivolumab treatment for cancer. The pathophysiology of lichen nitidus is unknown.

Lichen nitidus can occur in the presence of other skin conditions like lichen planus, atopic dermatitis, vitiligo, erythema nodosum, and lichen spinulosus. Histopathologic characteristics of lichen nitidus are described as a “ball and claw” of epidermal rete around a lymphohistiocytic infiltrate. Parakeratosis overlying epidermal atrophy and focal basal liquefaction degeneration is also seen.

The differential diagnosis of lichen nitidus includes flat warts, which can present as clusters of small flat-topped papules that can show a pseudo-Koebner phenomenon (where the virus is seeded in traumatized skin). The morphological difference between the condition is that lichen nitidus lesions are usually monomorphic, compared with flat warts, which usually present with different sizes and shapes.

Patients with a history of allergic contact dermatitis may present with a generalized monomorphic eruption of skin-colored papules (known as ID reaction) that can sometimes be very similar to lichen nitidus. Allergic contact dermatitis tends to respond fairly quickly to topical or systemic corticosteroids, unlike lichen nitidus. There are a few reports that consider lichen nitidus to be a variant of lichen planus, although they have different histopathologic findings. Lichen planus lesions are described as polygonal, pruritic, purple to pink papules most commonly seen on the wrists, lower back, and ankles. Lichen planus can be seen in patients with hepatitis C and may also occur secondary to medication.

Milia are small keratin cysts on the skin that are commonly seen in babies as primary milia and can be seen in older children secondary to trauma (commonly on the eyelids) or medications. Given their size and monomorphic appearance, they can sometimes be confused with lichen nitidus.

Lichen nitidus is often asymptomatic and the lesions resolve within a few months to years. Topical corticosteroids can be helpful to alleviate the symptoms in patients who present with pruritus. In more persistent and generalized cases, phototherapy, systemic corticosteroids, acitretin, isotretinoin, or cyclosporine can be considered.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.

References

Chu J and Lam JM. CMAJ. 2014 Dec 9;186(18):E688.

Lestringant G et al. Dermatology 1996;192:171-3.

Peterson JA et al. Proc (Bayl Univ Med Cent). 2021 Aug 25;35(1):70-2.

Schwartz C and Goodman MB. “Lichen nitidus,” in StatPearls. Treasure Island, Fla.: StatPearls Publishing, 2022.

The patient was diagnosed with lichen nitidus, given the characteristic clinical presentation.

Lichen nitidus is a rare chronic inflammatory condition of the skin that most commonly presents in children and young adults and does not seem to be restricted to any sex or race. The classic lesions are described as asymptomatic to slightly pruritic, small (1 mm), skin-colored to hypopigmented flat-topped papules.

Koebner phenomenon is usually seen in which the skin lesions appear in areas of traumatized healthy skin. The extremities, abdomen, chest, and penis are common locations for the lesions to occur. Rarely, the oral mucosa or nails can be involved. It has been described in patients with a diagnosis of Crohn’s disease, Niemann-Pick disease, Down syndrome, and HIV. The rare, generalized purpuric variant has been reported in a few cases associated with interferon and ribavirin treatment for hepatitis C infection and nivolumab treatment for cancer. The pathophysiology of lichen nitidus is unknown.

Lichen nitidus can occur in the presence of other skin conditions like lichen planus, atopic dermatitis, vitiligo, erythema nodosum, and lichen spinulosus. Histopathologic characteristics of lichen nitidus are described as a “ball and claw” of epidermal rete around a lymphohistiocytic infiltrate. Parakeratosis overlying epidermal atrophy and focal basal liquefaction degeneration is also seen.

The differential diagnosis of lichen nitidus includes flat warts, which can present as clusters of small flat-topped papules that can show a pseudo-Koebner phenomenon (where the virus is seeded in traumatized skin). The morphological difference between the condition is that lichen nitidus lesions are usually monomorphic, compared with flat warts, which usually present with different sizes and shapes.

Patients with a history of allergic contact dermatitis may present with a generalized monomorphic eruption of skin-colored papules (known as ID reaction) that can sometimes be very similar to lichen nitidus. Allergic contact dermatitis tends to respond fairly quickly to topical or systemic corticosteroids, unlike lichen nitidus. There are a few reports that consider lichen nitidus to be a variant of lichen planus, although they have different histopathologic findings. Lichen planus lesions are described as polygonal, pruritic, purple to pink papules most commonly seen on the wrists, lower back, and ankles. Lichen planus can be seen in patients with hepatitis C and may also occur secondary to medication.

Milia are small keratin cysts on the skin that are commonly seen in babies as primary milia and can be seen in older children secondary to trauma (commonly on the eyelids) or medications. Given their size and monomorphic appearance, they can sometimes be confused with lichen nitidus.

Lichen nitidus is often asymptomatic and the lesions resolve within a few months to years. Topical corticosteroids can be helpful to alleviate the symptoms in patients who present with pruritus. In more persistent and generalized cases, phototherapy, systemic corticosteroids, acitretin, isotretinoin, or cyclosporine can be considered.

Dr. Matiz is a pediatric dermatologist at Southern California Permanente Medical Group, San Diego.

References

Chu J and Lam JM. CMAJ. 2014 Dec 9;186(18):E688.

Lestringant G et al. Dermatology 1996;192:171-3.

Peterson JA et al. Proc (Bayl Univ Med Cent). 2021 Aug 25;35(1):70-2.

Schwartz C and Goodman MB. “Lichen nitidus,” in StatPearls. Treasure Island, Fla.: StatPearls Publishing, 2022.