Nektarios Lountzis, MD

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.

The Diagnosis: Levamisole-Induced Vasculopathy

Biopsy of one of the bullous retiform purpura on the leg (Figure 1) revealed a combined leukocytoclastic vasculitis and thrombotic vasculopathy (quiz images). Periodic acid-Schiff and Gram stains, with adequate controls, were negative for pathogenic fungal and bacterial organisms. Although this reaction pattern has an extensive differential, in this clinical setting with associated cocaine-positive urine toxicologic analysis, perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and leukopenia, the histopathologic findings were consistent with levamisole-induced vasculopathy (LIV).^1,2 Although not specific, leukocytoclastic vasculitis and thrombotic vasculopathy have been reported as the classic histopathologic findings of LIV. In addition, interstitial and perivascular neovascularization have been reported as a potential histopathologic finding associated with this entity but was not seen in our case.³  

Levamisole is an anthelminthic agent used to adulterate cocaine, a practice first noted in 2003 with increasing incidence.¹ Both levamisole and cocaine stimulate the sympathetic nervous system by increasing dopamine in the euphoric areas of the brain.^1,3 By combining the 2 substances, preparation costs are reduced and stimulant effects are enhanced. It is estimated that 69% to 80% of cocaine in the United States is contaminated with levamisole.^2,4,5 The constellation of findings seen in patients abusing levamisole-contaminated cocaine include agranulocytosis; p-ANCA; and a tender, vasculitic, retiform purpura presentation. The most common sites for the purpura include the cheeks and ears. The purpura can progress to bullous lesions, as seen in our patient, followed by necrosis.^4,6 Recurrent use of levamisole-contaminated cocaine is associated with recurrent agranulocytosis and classic skin findings, which is suggestive of a causal relationship.⁶  

Serologic testing for levamisole exposure presents a challenge. The half-life of levamisole is relatively short (estimated at 5.6 hours) and is found in urine samples approximately 3% of the time.^1,3,6 The volatile diagnostic characteristics of levamisole make concrete laboratory confirmation difficult. Although a skin biopsy can be helpful to rule out other causes of vasculitislike presentations, it is not specific for LIV. Therefore, clinical suspicion for LIV should remain high in patients who present with the cutaneous findings described as well as agranulocytosis, positive p-ANCA, and a history of cocaine use with a skin biopsy showing leukocytoclastic vasculitis and thrombotic vasculopathy.  

The differential diagnosis for LIV with retiform bullous lesions includes several other vasculitides and vesiculobullous diseases. Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystem vasculitis that is characterized by eosinophilia, asthma, and rhinosinusitis. Eosinophilic granulomatosis with polyangiitis primarily affects small and medium arteries in the skin and respiratory tract and occurs in 3 stages: prodromal, eosinophilic, and vasculitic. These stages are characterized by mild asthma or rhinitis, eosinophilia with multiorgan infiltration, and vasculitis with extravascular granulomatosis, respectively. Diagnosis often is clinical based on these findings and laboratory evaluation. Eosinophilic granulomatosis with polyangiitis presents with positive p-ANCA in 40% to 60% of patients.⁷ The vasculitis stage of EGPA presents with cutaneous findings in 60% of cases, including palpable purpura, infiltrated papules and plaques, urticaria, necrotizing lesions, and rarely vesicles and bullae.⁸ Classic histopathologic features include leukocytoclastic or eosinophilic vasculitis, an eosinophilic infiltrate, granuloma formation, and eosinophilic granule deposition onto collagen fibrils (otherwise known as flame figures)(Figure 2). Biopsy of these lesions with the aforementioned findings, in constellation with the described systemic signs and symptoms, can aid in diagnosis of EGPA.  

Polyarteritis nodosa (PAN) is a vasculitis that can be either multisystem or limited to one organ. Classic PAN affects the small- to medium-sized vessels. When there is multisystem involvement, it most often affects the skin, gastrointestinal tract, and kidneys. It presents with subcutaneous or dermal nodules, necrotic lesions, livedo reticularis, hypertension, abdominal pain, and an acute abdomen.⁹ When PAN is in its limited form, it most commonly occurs in the skin. The cutaneous manifestations of skin-limited PAN are identical to classic PAN, most commonly occurring on the legs and arms and less often on the trunk, head, and neck.¹⁰ To aid in diagnosis, biopsies of cutaneous lesions are beneficial. Dermatopathologic examination of PAN reveals fibrinoid necrosis of small and medium vessels with a perivascular mononuclear inflammatory infiltrate (Figure 3). Cutaneous PAN rarely progresses to multisystem classic PAN and carries a more favorable prognosis.  

Microvascular occlusion syndromes can result in clinical presentations that resemble LIV. Idiopathic thrombocytopenic purpura is a hematologic autoimmune condition resulting in destruction of platelets and subsequent thrombocytopenia. Idiopathic thrombocytopenic purpura can be either primary or secondary to infections, drugs, malignancy, or other autoimmune conditions. Clinically, it presents as mucosal or cutaneous bleeding, epistaxis, hematochezia, or hematuria and can result in substantial hemorrhage. On the skin, it can appear as petechiae and ecchymoses in dependent areas and rarely hemorrhagic bullae of the skin and mucous membranes in cases of severe thrombocytopenia.^11,12 Biopsies of these lesions will show notable extravasation of red blood cells with incipient hemorrhagic bullae formation (Figure 4). Recognition of hemorrhagic bullae as a presentation of idiopathic thrombocytopenic purpura is critical to identifying severe underlying disease.  

Beyond other vasculitides and microvascular occlusion syndromes, vessel-invasive microorganisms can result in similar histopathologic and clinical presentations to LIV. Ecthyma gangrenosum (EG) is a septic vasculitis, often caused by Pseudomonas aeruginosa, usually affecting immunocompromised patients. Ecthyma gangrenosum presents with vesiculobullous lesions with erythematous violaceous borders that develop into hemorrhagic bullae with necrotic centers.¹³ Biopsy of EG will show vascular occlusion and basophilic granular material within or around vessels, suggestive of bacterial sepsis (Figure 5). The detection of an infectious agent on histopathology allows one to easily distinguish between EG and LIV.  

The Diagnosis: Levamisole-Induced Vasculopathy

Biopsy of one of the bullous retiform purpura on the leg (Figure 1) revealed a combined leukocytoclastic vasculitis and thrombotic vasculopathy (quiz images). Periodic acid-Schiff and Gram stains, with adequate controls, were negative for pathogenic fungal and bacterial organisms. Although this reaction pattern has an extensive differential, in this clinical setting with associated cocaine-positive urine toxicologic analysis, perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and leukopenia, the histopathologic findings were consistent with levamisole-induced vasculopathy (LIV).^1,2 Although not specific, leukocytoclastic vasculitis and thrombotic vasculopathy have been reported as the classic histopathologic findings of LIV. In addition, interstitial and perivascular neovascularization have been reported as a potential histopathologic finding associated with this entity but was not seen in our case.³  

Levamisole is an anthelminthic agent used to adulterate cocaine, a practice first noted in 2003 with increasing incidence.¹ Both levamisole and cocaine stimulate the sympathetic nervous system by increasing dopamine in the euphoric areas of the brain.^1,3 By combining the 2 substances, preparation costs are reduced and stimulant effects are enhanced. It is estimated that 69% to 80% of cocaine in the United States is contaminated with levamisole.^2,4,5 The constellation of findings seen in patients abusing levamisole-contaminated cocaine include agranulocytosis; p-ANCA; and a tender, vasculitic, retiform purpura presentation. The most common sites for the purpura include the cheeks and ears. The purpura can progress to bullous lesions, as seen in our patient, followed by necrosis.^4,6 Recurrent use of levamisole-contaminated cocaine is associated with recurrent agranulocytosis and classic skin findings, which is suggestive of a causal relationship.⁶  

Serologic testing for levamisole exposure presents a challenge. The half-life of levamisole is relatively short (estimated at 5.6 hours) and is found in urine samples approximately 3% of the time.^1,3,6 The volatile diagnostic characteristics of levamisole make concrete laboratory confirmation difficult. Although a skin biopsy can be helpful to rule out other causes of vasculitislike presentations, it is not specific for LIV. Therefore, clinical suspicion for LIV should remain high in patients who present with the cutaneous findings described as well as agranulocytosis, positive p-ANCA, and a history of cocaine use with a skin biopsy showing leukocytoclastic vasculitis and thrombotic vasculopathy.  

The differential diagnosis for LIV with retiform bullous lesions includes several other vasculitides and vesiculobullous diseases. Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystem vasculitis that is characterized by eosinophilia, asthma, and rhinosinusitis. Eosinophilic granulomatosis with polyangiitis primarily affects small and medium arteries in the skin and respiratory tract and occurs in 3 stages: prodromal, eosinophilic, and vasculitic. These stages are characterized by mild asthma or rhinitis, eosinophilia with multiorgan infiltration, and vasculitis with extravascular granulomatosis, respectively. Diagnosis often is clinical based on these findings and laboratory evaluation. Eosinophilic granulomatosis with polyangiitis presents with positive p-ANCA in 40% to 60% of patients.⁷ The vasculitis stage of EGPA presents with cutaneous findings in 60% of cases, including palpable purpura, infiltrated papules and plaques, urticaria, necrotizing lesions, and rarely vesicles and bullae.⁸ Classic histopathologic features include leukocytoclastic or eosinophilic vasculitis, an eosinophilic infiltrate, granuloma formation, and eosinophilic granule deposition onto collagen fibrils (otherwise known as flame figures)(Figure 2). Biopsy of these lesions with the aforementioned findings, in constellation with the described systemic signs and symptoms, can aid in diagnosis of EGPA.  

Polyarteritis nodosa (PAN) is a vasculitis that can be either multisystem or limited to one organ. Classic PAN affects the small- to medium-sized vessels. When there is multisystem involvement, it most often affects the skin, gastrointestinal tract, and kidneys. It presents with subcutaneous or dermal nodules, necrotic lesions, livedo reticularis, hypertension, abdominal pain, and an acute abdomen.⁹ When PAN is in its limited form, it most commonly occurs in the skin. The cutaneous manifestations of skin-limited PAN are identical to classic PAN, most commonly occurring on the legs and arms and less often on the trunk, head, and neck.¹⁰ To aid in diagnosis, biopsies of cutaneous lesions are beneficial. Dermatopathologic examination of PAN reveals fibrinoid necrosis of small and medium vessels with a perivascular mononuclear inflammatory infiltrate (Figure 3). Cutaneous PAN rarely progresses to multisystem classic PAN and carries a more favorable prognosis.  

Microvascular occlusion syndromes can result in clinical presentations that resemble LIV. Idiopathic thrombocytopenic purpura is a hematologic autoimmune condition resulting in destruction of platelets and subsequent thrombocytopenia. Idiopathic thrombocytopenic purpura can be either primary or secondary to infections, drugs, malignancy, or other autoimmune conditions. Clinically, it presents as mucosal or cutaneous bleeding, epistaxis, hematochezia, or hematuria and can result in substantial hemorrhage. On the skin, it can appear as petechiae and ecchymoses in dependent areas and rarely hemorrhagic bullae of the skin and mucous membranes in cases of severe thrombocytopenia.^11,12 Biopsies of these lesions will show notable extravasation of red blood cells with incipient hemorrhagic bullae formation (Figure 4). Recognition of hemorrhagic bullae as a presentation of idiopathic thrombocytopenic purpura is critical to identifying severe underlying disease.  

Beyond other vasculitides and microvascular occlusion syndromes, vessel-invasive microorganisms can result in similar histopathologic and clinical presentations to LIV. Ecthyma gangrenosum (EG) is a septic vasculitis, often caused by Pseudomonas aeruginosa, usually affecting immunocompromised patients. Ecthyma gangrenosum presents with vesiculobullous lesions with erythematous violaceous borders that develop into hemorrhagic bullae with necrotic centers.¹³ Biopsy of EG will show vascular occlusion and basophilic granular material within or around vessels, suggestive of bacterial sepsis (Figure 5). The detection of an infectious agent on histopathology allows one to easily distinguish between EG and LIV.  

The Diagnosis: Levamisole-Induced Vasculopathy

Biopsy of one of the bullous retiform purpura on the leg (Figure 1) revealed a combined leukocytoclastic vasculitis and thrombotic vasculopathy (quiz images). Periodic acid-Schiff and Gram stains, with adequate controls, were negative for pathogenic fungal and bacterial organisms. Although this reaction pattern has an extensive differential, in this clinical setting with associated cocaine-positive urine toxicologic analysis, perinuclear antineutrophil cytoplasmic antibodies (p-ANCA), and leukopenia, the histopathologic findings were consistent with levamisole-induced vasculopathy (LIV).^1,2 Although not specific, leukocytoclastic vasculitis and thrombotic vasculopathy have been reported as the classic histopathologic findings of LIV. In addition, interstitial and perivascular neovascularization have been reported as a potential histopathologic finding associated with this entity but was not seen in our case.³  

Levamisole is an anthelminthic agent used to adulterate cocaine, a practice first noted in 2003 with increasing incidence.¹ Both levamisole and cocaine stimulate the sympathetic nervous system by increasing dopamine in the euphoric areas of the brain.^1,3 By combining the 2 substances, preparation costs are reduced and stimulant effects are enhanced. It is estimated that 69% to 80% of cocaine in the United States is contaminated with levamisole.^2,4,5 The constellation of findings seen in patients abusing levamisole-contaminated cocaine include agranulocytosis; p-ANCA; and a tender, vasculitic, retiform purpura presentation. The most common sites for the purpura include the cheeks and ears. The purpura can progress to bullous lesions, as seen in our patient, followed by necrosis.^4,6 Recurrent use of levamisole-contaminated cocaine is associated with recurrent agranulocytosis and classic skin findings, which is suggestive of a causal relationship.⁶  

Serologic testing for levamisole exposure presents a challenge. The half-life of levamisole is relatively short (estimated at 5.6 hours) and is found in urine samples approximately 3% of the time.^1,3,6 The volatile diagnostic characteristics of levamisole make concrete laboratory confirmation difficult. Although a skin biopsy can be helpful to rule out other causes of vasculitislike presentations, it is not specific for LIV. Therefore, clinical suspicion for LIV should remain high in patients who present with the cutaneous findings described as well as agranulocytosis, positive p-ANCA, and a history of cocaine use with a skin biopsy showing leukocytoclastic vasculitis and thrombotic vasculopathy.  

The differential diagnosis for LIV with retiform bullous lesions includes several other vasculitides and vesiculobullous diseases. Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystem vasculitis that is characterized by eosinophilia, asthma, and rhinosinusitis. Eosinophilic granulomatosis with polyangiitis primarily affects small and medium arteries in the skin and respiratory tract and occurs in 3 stages: prodromal, eosinophilic, and vasculitic. These stages are characterized by mild asthma or rhinitis, eosinophilia with multiorgan infiltration, and vasculitis with extravascular granulomatosis, respectively. Diagnosis often is clinical based on these findings and laboratory evaluation. Eosinophilic granulomatosis with polyangiitis presents with positive p-ANCA in 40% to 60% of patients.⁷ The vasculitis stage of EGPA presents with cutaneous findings in 60% of cases, including palpable purpura, infiltrated papules and plaques, urticaria, necrotizing lesions, and rarely vesicles and bullae.⁸ Classic histopathologic features include leukocytoclastic or eosinophilic vasculitis, an eosinophilic infiltrate, granuloma formation, and eosinophilic granule deposition onto collagen fibrils (otherwise known as flame figures)(Figure 2). Biopsy of these lesions with the aforementioned findings, in constellation with the described systemic signs and symptoms, can aid in diagnosis of EGPA.  

Polyarteritis nodosa (PAN) is a vasculitis that can be either multisystem or limited to one organ. Classic PAN affects the small- to medium-sized vessels. When there is multisystem involvement, it most often affects the skin, gastrointestinal tract, and kidneys. It presents with subcutaneous or dermal nodules, necrotic lesions, livedo reticularis, hypertension, abdominal pain, and an acute abdomen.⁹ When PAN is in its limited form, it most commonly occurs in the skin. The cutaneous manifestations of skin-limited PAN are identical to classic PAN, most commonly occurring on the legs and arms and less often on the trunk, head, and neck.¹⁰ To aid in diagnosis, biopsies of cutaneous lesions are beneficial. Dermatopathologic examination of PAN reveals fibrinoid necrosis of small and medium vessels with a perivascular mononuclear inflammatory infiltrate (Figure 3). Cutaneous PAN rarely progresses to multisystem classic PAN and carries a more favorable prognosis.  

Microvascular occlusion syndromes can result in clinical presentations that resemble LIV. Idiopathic thrombocytopenic purpura is a hematologic autoimmune condition resulting in destruction of platelets and subsequent thrombocytopenia. Idiopathic thrombocytopenic purpura can be either primary or secondary to infections, drugs, malignancy, or other autoimmune conditions. Clinically, it presents as mucosal or cutaneous bleeding, epistaxis, hematochezia, or hematuria and can result in substantial hemorrhage. On the skin, it can appear as petechiae and ecchymoses in dependent areas and rarely hemorrhagic bullae of the skin and mucous membranes in cases of severe thrombocytopenia.^11,12 Biopsies of these lesions will show notable extravasation of red blood cells with incipient hemorrhagic bullae formation (Figure 4). Recognition of hemorrhagic bullae as a presentation of idiopathic thrombocytopenic purpura is critical to identifying severe underlying disease.  

Beyond other vasculitides and microvascular occlusion syndromes, vessel-invasive microorganisms can result in similar histopathologic and clinical presentations to LIV. Ecthyma gangrenosum (EG) is a septic vasculitis, often caused by Pseudomonas aeruginosa, usually affecting immunocompromised patients. Ecthyma gangrenosum presents with vesiculobullous lesions with erythematous violaceous borders that develop into hemorrhagic bullae with necrotic centers.¹³ Biopsy of EG will show vascular occlusion and basophilic granular material within or around vessels, suggestive of bacterial sepsis (Figure 5). The detection of an infectious agent on histopathology allows one to easily distinguish between EG and LIV.  

To the Editor:

Lymphomatoid papulosis (LyP) is a chronic, recurring, self-healing, primary cutaneous lymphoproliferative disorder. This disease affects patients of all ages but most commonly presents in the fifth decade with a slight male predominance.¹ The estimated worldwide incidence is 1.2 to 1.9 cases per 1,000,000 individuals, and the 10-year survival rate is close to 100%.¹ Clinically, LyP presents as a few to more than 100 red-brown papules or nodules, some with hemorrhagic crust or central necrosis, often occurring in crops and in various stages of evolution. They most commonly are distributed on the trunk and extremities; however, the face, scalp, and oral mucosa rarely may be involved. Each lesion may last on average 3 to 8 weeks, with residual hyperpigmentation or hypopigmentation of the skin or superficial varioliform scars. The clinical characteristic of spontaneous regression is crucial for distinguishing LyP from other forms of cutaneous lymphoma.² The disease course is variable, lasting anywhere from a few months to decades. Histopathologically, LyP consists of a frequently CD30⁺ lymphocytic proliferation in multiple described patterns.¹ We report a case of LyP in a patient who initially presented with pink edematous papules and vesicles that progressed to crusted ulcerations, nodules, and deep necrotic eschars on the scalp, neck, and upper trunk. Multiple biopsies and T-cell gene rearrangement studies were necessary to make the diagnosis.

A 73-year-old man presented with edematous crusted papules and nodules as well as scarring with serous drainage on the scalp and upper trunk of several months’ duration. He also reported pain and pruritus. He had a medical history of B-cell CD20⁻ chronic lymphocytic leukemia (CLL) that was treated with fludarabine, cyclophosphamide, rituximab, and intravenous immunoglobulin approximately one year prior and currently was in remission; prostate cancer treated with prostatectomy; hypertension; and type 2 diabetes mellitus. His medications included metoprolol, valsartan, and glipizide.

Histopathology revealed a hypersensitivity reaction, and the clinicopathologic correlation was believed to represent an exuberant arthropod bite reaction in the setting of CLL. The eruption responded well to oral prednisone and topical corticosteroids but recurred when the medications were withdrawn. A repeat biopsy resulted in a diagnosis of atypical eosinophil-predominant Sweet syndrome. The condition resolved.

Three years later he developed multiple honey-crusted, superficial ulcers as well as serous, fluid-filled vesiculobullae on the head. A tissue culture revealed Proteus mirabilis, Staphylococcus aureus, and Enterococcus faecalis, and was negative for acid-fast bacteria and fungus. Biopsy of these lesions revealed dermal ulceration with a mixed inflammatory infiltrate and numerous eosinophils as well as a few clustered CD30⁺ cells; direct immunofluorescence was negative. An extensive laboratory workup including bullous pemphigoid antigens, C-reactive protein, antinuclear antibodies comprehensive profile, antineutrophil cytoplasmic antibodies, rheumatoid factor, anticyclic citrullinated peptide antibodies, serum protein electrophoresis, lactate dehydrogenase, complete blood cell count with differential, complete metabolic profile, thyroid-stimulating hormone, uric acid, C3, C4, immunoglobulin profile, angiotensin-converting enzyme level, and urinalysis was unremarkable. He improved with courses of minocycline, prednisone, and topical clobetasol, but he had periodic and progressive flares over several months with punched-out crusted ulcerations developing on the scalp (Figure 1A) and neck (Figure 1B). The oral and ocular mucosae were uninvolved, but the nasal mucosa had some involvement.

There is no cure for LyP and data regarding the potential of aggressive therapy on the prevention of secondary lymphomas is lacking. Wieser et al¹ reported that treatment did not prevent the progression to lymphoma in their retrospective analysis of 180 patients. The number of lesions, frequency of outbreaks, and extent of the scarring can dictate the treatment approach for LyP. Conservative topical therapies include corticosteroids, bexarotene, and imiquimod. Mupirocin may help to prevent infection of ulcerated lesions.^1,2 Low-dose methotrexate has been shown to be the most efficacious treatment in reducing the number of lesions, particularly for scarring or cosmetically sensitive areas. Oral methotrexate at a dosage of 10 mg to 25 mg weekly tapered to the lowest effective dose may suppress outbreaks of LyP lesions.^1,2 Other therapies include psoralen plus UVA, UVB, interferon alfa-2a, oral bexarotene, oral acyclovir or valacyclovir, etretinate, mycophenolic acid, photodynamic therapy, oral antibiotics, excision, and radiotherapy.^1,2 Systemic chemotherapy and total-skin electron beam therapy have shown efficacy in clearing the lesions; however, the disease recurs after discontinuation of therapy.² Systemic chemotherapy is not recommended for the treatment of LyP, as risks outweigh the benefits and it does not reduce the risk for developing lymphoma.¹ The prognosis generally is good, though long-term follow-up is imperative to monitor for the development of other lymphomas.

Our patient presented with LyP a few months after completing chemotherapy for his CLL. It is unknown if he developed LyP just before the time of presentation, or if he may have developed it at the same time as his CLL by a common inciting event. In the latter case, it is speculative that the LyP may have been controlled by chemotherapy for his CLL, only to become clinically apparent after discontinuation, then naturally remit for a longer period. Case reports such as ours with unusual clinical presentations, B-cell lymphoma associations, and unique timing of lymphoma onset may help to provide insight into the pathogenesis of this disease.

We highlighted an unusual case of LyP that presented clinically with crusted ulcerations as well as vesiculobullous and edematous papules that progressed into deep punched-out ulcers with eschars, nodules, and scarring on the head and upper trunk. Lymphomatoid papulosis can be difficult to diagnose histopathologically at the early stages, and multiple repeat biopsies may be necessary to confirm the diagnosis. T-cell gene rearrangement and immunohistochemistry studies are helpful along with clinical correlation to establish a diagnosis in these cases. We recommend that physicians keep LyP on the differential diagnosis for patients with similar clinical presentations and remain vigilant in monitoring for the development of secondary lymphoma.

To the Editor:

Lymphomatoid papulosis (LyP) is a chronic, recurring, self-healing, primary cutaneous lymphoproliferative disorder. This disease affects patients of all ages but most commonly presents in the fifth decade with a slight male predominance.¹ The estimated worldwide incidence is 1.2 to 1.9 cases per 1,000,000 individuals, and the 10-year survival rate is close to 100%.¹ Clinically, LyP presents as a few to more than 100 red-brown papules or nodules, some with hemorrhagic crust or central necrosis, often occurring in crops and in various stages of evolution. They most commonly are distributed on the trunk and extremities; however, the face, scalp, and oral mucosa rarely may be involved. Each lesion may last on average 3 to 8 weeks, with residual hyperpigmentation or hypopigmentation of the skin or superficial varioliform scars. The clinical characteristic of spontaneous regression is crucial for distinguishing LyP from other forms of cutaneous lymphoma.² The disease course is variable, lasting anywhere from a few months to decades. Histopathologically, LyP consists of a frequently CD30⁺ lymphocytic proliferation in multiple described patterns.¹ We report a case of LyP in a patient who initially presented with pink edematous papules and vesicles that progressed to crusted ulcerations, nodules, and deep necrotic eschars on the scalp, neck, and upper trunk. Multiple biopsies and T-cell gene rearrangement studies were necessary to make the diagnosis.

A 73-year-old man presented with edematous crusted papules and nodules as well as scarring with serous drainage on the scalp and upper trunk of several months’ duration. He also reported pain and pruritus. He had a medical history of B-cell CD20⁻ chronic lymphocytic leukemia (CLL) that was treated with fludarabine, cyclophosphamide, rituximab, and intravenous immunoglobulin approximately one year prior and currently was in remission; prostate cancer treated with prostatectomy; hypertension; and type 2 diabetes mellitus. His medications included metoprolol, valsartan, and glipizide.

Histopathology revealed a hypersensitivity reaction, and the clinicopathologic correlation was believed to represent an exuberant arthropod bite reaction in the setting of CLL. The eruption responded well to oral prednisone and topical corticosteroids but recurred when the medications were withdrawn. A repeat biopsy resulted in a diagnosis of atypical eosinophil-predominant Sweet syndrome. The condition resolved.

Three years later he developed multiple honey-crusted, superficial ulcers as well as serous, fluid-filled vesiculobullae on the head. A tissue culture revealed Proteus mirabilis, Staphylococcus aureus, and Enterococcus faecalis, and was negative for acid-fast bacteria and fungus. Biopsy of these lesions revealed dermal ulceration with a mixed inflammatory infiltrate and numerous eosinophils as well as a few clustered CD30⁺ cells; direct immunofluorescence was negative. An extensive laboratory workup including bullous pemphigoid antigens, C-reactive protein, antinuclear antibodies comprehensive profile, antineutrophil cytoplasmic antibodies, rheumatoid factor, anticyclic citrullinated peptide antibodies, serum protein electrophoresis, lactate dehydrogenase, complete blood cell count with differential, complete metabolic profile, thyroid-stimulating hormone, uric acid, C3, C4, immunoglobulin profile, angiotensin-converting enzyme level, and urinalysis was unremarkable. He improved with courses of minocycline, prednisone, and topical clobetasol, but he had periodic and progressive flares over several months with punched-out crusted ulcerations developing on the scalp (Figure 1A) and neck (Figure 1B). The oral and ocular mucosae were uninvolved, but the nasal mucosa had some involvement.

There is no cure for LyP and data regarding the potential of aggressive therapy on the prevention of secondary lymphomas is lacking. Wieser et al¹ reported that treatment did not prevent the progression to lymphoma in their retrospective analysis of 180 patients. The number of lesions, frequency of outbreaks, and extent of the scarring can dictate the treatment approach for LyP. Conservative topical therapies include corticosteroids, bexarotene, and imiquimod. Mupirocin may help to prevent infection of ulcerated lesions.^1,2 Low-dose methotrexate has been shown to be the most efficacious treatment in reducing the number of lesions, particularly for scarring or cosmetically sensitive areas. Oral methotrexate at a dosage of 10 mg to 25 mg weekly tapered to the lowest effective dose may suppress outbreaks of LyP lesions.^1,2 Other therapies include psoralen plus UVA, UVB, interferon alfa-2a, oral bexarotene, oral acyclovir or valacyclovir, etretinate, mycophenolic acid, photodynamic therapy, oral antibiotics, excision, and radiotherapy.^1,2 Systemic chemotherapy and total-skin electron beam therapy have shown efficacy in clearing the lesions; however, the disease recurs after discontinuation of therapy.² Systemic chemotherapy is not recommended for the treatment of LyP, as risks outweigh the benefits and it does not reduce the risk for developing lymphoma.¹ The prognosis generally is good, though long-term follow-up is imperative to monitor for the development of other lymphomas.

Our patient presented with LyP a few months after completing chemotherapy for his CLL. It is unknown if he developed LyP just before the time of presentation, or if he may have developed it at the same time as his CLL by a common inciting event. In the latter case, it is speculative that the LyP may have been controlled by chemotherapy for his CLL, only to become clinically apparent after discontinuation, then naturally remit for a longer period. Case reports such as ours with unusual clinical presentations, B-cell lymphoma associations, and unique timing of lymphoma onset may help to provide insight into the pathogenesis of this disease.

We highlighted an unusual case of LyP that presented clinically with crusted ulcerations as well as vesiculobullous and edematous papules that progressed into deep punched-out ulcers with eschars, nodules, and scarring on the head and upper trunk. Lymphomatoid papulosis can be difficult to diagnose histopathologically at the early stages, and multiple repeat biopsies may be necessary to confirm the diagnosis. T-cell gene rearrangement and immunohistochemistry studies are helpful along with clinical correlation to establish a diagnosis in these cases. We recommend that physicians keep LyP on the differential diagnosis for patients with similar clinical presentations and remain vigilant in monitoring for the development of secondary lymphoma.

To the Editor:

Lymphomatoid papulosis (LyP) is a chronic, recurring, self-healing, primary cutaneous lymphoproliferative disorder. This disease affects patients of all ages but most commonly presents in the fifth decade with a slight male predominance.¹ The estimated worldwide incidence is 1.2 to 1.9 cases per 1,000,000 individuals, and the 10-year survival rate is close to 100%.¹ Clinically, LyP presents as a few to more than 100 red-brown papules or nodules, some with hemorrhagic crust or central necrosis, often occurring in crops and in various stages of evolution. They most commonly are distributed on the trunk and extremities; however, the face, scalp, and oral mucosa rarely may be involved. Each lesion may last on average 3 to 8 weeks, with residual hyperpigmentation or hypopigmentation of the skin or superficial varioliform scars. The clinical characteristic of spontaneous regression is crucial for distinguishing LyP from other forms of cutaneous lymphoma.² The disease course is variable, lasting anywhere from a few months to decades. Histopathologically, LyP consists of a frequently CD30⁺ lymphocytic proliferation in multiple described patterns.¹ We report a case of LyP in a patient who initially presented with pink edematous papules and vesicles that progressed to crusted ulcerations, nodules, and deep necrotic eschars on the scalp, neck, and upper trunk. Multiple biopsies and T-cell gene rearrangement studies were necessary to make the diagnosis.

A 73-year-old man presented with edematous crusted papules and nodules as well as scarring with serous drainage on the scalp and upper trunk of several months’ duration. He also reported pain and pruritus. He had a medical history of B-cell CD20⁻ chronic lymphocytic leukemia (CLL) that was treated with fludarabine, cyclophosphamide, rituximab, and intravenous immunoglobulin approximately one year prior and currently was in remission; prostate cancer treated with prostatectomy; hypertension; and type 2 diabetes mellitus. His medications included metoprolol, valsartan, and glipizide.

Histopathology revealed a hypersensitivity reaction, and the clinicopathologic correlation was believed to represent an exuberant arthropod bite reaction in the setting of CLL. The eruption responded well to oral prednisone and topical corticosteroids but recurred when the medications were withdrawn. A repeat biopsy resulted in a diagnosis of atypical eosinophil-predominant Sweet syndrome. The condition resolved.

Three years later he developed multiple honey-crusted, superficial ulcers as well as serous, fluid-filled vesiculobullae on the head. A tissue culture revealed Proteus mirabilis, Staphylococcus aureus, and Enterococcus faecalis, and was negative for acid-fast bacteria and fungus. Biopsy of these lesions revealed dermal ulceration with a mixed inflammatory infiltrate and numerous eosinophils as well as a few clustered CD30⁺ cells; direct immunofluorescence was negative. An extensive laboratory workup including bullous pemphigoid antigens, C-reactive protein, antinuclear antibodies comprehensive profile, antineutrophil cytoplasmic antibodies, rheumatoid factor, anticyclic citrullinated peptide antibodies, serum protein electrophoresis, lactate dehydrogenase, complete blood cell count with differential, complete metabolic profile, thyroid-stimulating hormone, uric acid, C3, C4, immunoglobulin profile, angiotensin-converting enzyme level, and urinalysis was unremarkable. He improved with courses of minocycline, prednisone, and topical clobetasol, but he had periodic and progressive flares over several months with punched-out crusted ulcerations developing on the scalp (Figure 1A) and neck (Figure 1B). The oral and ocular mucosae were uninvolved, but the nasal mucosa had some involvement.

There is no cure for LyP and data regarding the potential of aggressive therapy on the prevention of secondary lymphomas is lacking. Wieser et al¹ reported that treatment did not prevent the progression to lymphoma in their retrospective analysis of 180 patients. The number of lesions, frequency of outbreaks, and extent of the scarring can dictate the treatment approach for LyP. Conservative topical therapies include corticosteroids, bexarotene, and imiquimod. Mupirocin may help to prevent infection of ulcerated lesions.^1,2 Low-dose methotrexate has been shown to be the most efficacious treatment in reducing the number of lesions, particularly for scarring or cosmetically sensitive areas. Oral methotrexate at a dosage of 10 mg to 25 mg weekly tapered to the lowest effective dose may suppress outbreaks of LyP lesions.^1,2 Other therapies include psoralen plus UVA, UVB, interferon alfa-2a, oral bexarotene, oral acyclovir or valacyclovir, etretinate, mycophenolic acid, photodynamic therapy, oral antibiotics, excision, and radiotherapy.^1,2 Systemic chemotherapy and total-skin electron beam therapy have shown efficacy in clearing the lesions; however, the disease recurs after discontinuation of therapy.² Systemic chemotherapy is not recommended for the treatment of LyP, as risks outweigh the benefits and it does not reduce the risk for developing lymphoma.¹ The prognosis generally is good, though long-term follow-up is imperative to monitor for the development of other lymphomas.

Our patient presented with LyP a few months after completing chemotherapy for his CLL. It is unknown if he developed LyP just before the time of presentation, or if he may have developed it at the same time as his CLL by a common inciting event. In the latter case, it is speculative that the LyP may have been controlled by chemotherapy for his CLL, only to become clinically apparent after discontinuation, then naturally remit for a longer period. Case reports such as ours with unusual clinical presentations, B-cell lymphoma associations, and unique timing of lymphoma onset may help to provide insight into the pathogenesis of this disease.

We highlighted an unusual case of LyP that presented clinically with crusted ulcerations as well as vesiculobullous and edematous papules that progressed into deep punched-out ulcers with eschars, nodules, and scarring on the head and upper trunk. Lymphomatoid papulosis can be difficult to diagnose histopathologically at the early stages, and multiple repeat biopsies may be necessary to confirm the diagnosis. T-cell gene rearrangement and immunohistochemistry studies are helpful along with clinical correlation to establish a diagnosis in these cases. We recommend that physicians keep LyP on the differential diagnosis for patients with similar clinical presentations and remain vigilant in monitoring for the development of secondary lymphoma.

To the Editor:

A 71-year-old man presented with a nodule on the vertex of the scalp of 1 year’s duration. The lesion had become soft and tender during the week prior to presentation. He noted that he was experiencing headaches and a buzzing sound in his head. He denied all other neurologic symptoms. The patient was given amoxicillin from a primary care physician and was referred to our institution for evaluation of a presumed inflamed cyst.

The patient’s medical history included an intracranial arteriovenous fistula (AVF) treated with endovascular embolization 1 year prior to presentation, 2 substantial falls in childhood with head trauma and loss of consciousness, essential hypertension, and an aortic aneurysm. His medications included amlodipine, lisinopril, amoxicillin, a multivitamin, and grape seed extract.

Physical examination revealed a 2-cm, pink, somewhat rubbery, subcutaneous, nonmobile nodule on the vertex of the scalp (Figure 1). The lesion was not consistent with a common pilar cyst, and an excisional biopsy was performed to exclude malignancy. Upon superficial incision, the lesion bled moderately, and the procedure was immediately discontinued. Hemostasis was obtained, and the patient was sent for ultrasonography of the lesion.

The diagnosis of an S-AVF is confirmed with imaging studies. Doppler ultrasonography initially will help to detect that a lesion is vascular in nature. Intra-arterial digital subtraction angiography is the gold-standard imaging technique and is necessary to delineate the feeding arteries and the draining channels as well as possible communication with intracranial vasculature.^1,2 There is controversy regarding the appropriate treatment of S-AVFs.² Each S-AVF possesses unique anatomic features that dictate appropriate management. The prognosis for an S-AVF is extremely variable, and the decision to treat is based on the patient’s symptoms and risk for exsanguinating hemorrhage.^2,4 Neurosurgical approaches include ligation of the feeding arteries, surgical resection, electrothrombosis, direct intralesional injection of sclerosing agents, and endovascular embolization. Endovascular intervention increasingly is utilized as a primary treatment or as a preoperative adjunct to surgery.^2,4 Large S-AVFs have a high risk for recurrence after treatment with endovascular embolization alone. In cases with intracranial communication, the intracranial component is treated first.²

This case emphasizes the importance of including S-AVFs on the dermatologic differential diagnosis of a scalp nodule, especially in patients with any history of intracranial AVF. A thorough history, detailed intake of potential signs and symptoms of AVF, and palpation for bruits is recommended as part of the surgical evaluation of a scalp nodule. Imaging of scalp nodules also should be considered for patients with any history of intracranial AVF; S-AVFs should be referred to neurosurgery or interventional neuroradiology for evaluation and possible treatment.

To the Editor:

A 71-year-old man presented with a nodule on the vertex of the scalp of 1 year’s duration. The lesion had become soft and tender during the week prior to presentation. He noted that he was experiencing headaches and a buzzing sound in his head. He denied all other neurologic symptoms. The patient was given amoxicillin from a primary care physician and was referred to our institution for evaluation of a presumed inflamed cyst.

The patient’s medical history included an intracranial arteriovenous fistula (AVF) treated with endovascular embolization 1 year prior to presentation, 2 substantial falls in childhood with head trauma and loss of consciousness, essential hypertension, and an aortic aneurysm. His medications included amlodipine, lisinopril, amoxicillin, a multivitamin, and grape seed extract.

Physical examination revealed a 2-cm, pink, somewhat rubbery, subcutaneous, nonmobile nodule on the vertex of the scalp (Figure 1). The lesion was not consistent with a common pilar cyst, and an excisional biopsy was performed to exclude malignancy. Upon superficial incision, the lesion bled moderately, and the procedure was immediately discontinued. Hemostasis was obtained, and the patient was sent for ultrasonography of the lesion.

The diagnosis of an S-AVF is confirmed with imaging studies. Doppler ultrasonography initially will help to detect that a lesion is vascular in nature. Intra-arterial digital subtraction angiography is the gold-standard imaging technique and is necessary to delineate the feeding arteries and the draining channels as well as possible communication with intracranial vasculature.^1,2 There is controversy regarding the appropriate treatment of S-AVFs.² Each S-AVF possesses unique anatomic features that dictate appropriate management. The prognosis for an S-AVF is extremely variable, and the decision to treat is based on the patient’s symptoms and risk for exsanguinating hemorrhage.^2,4 Neurosurgical approaches include ligation of the feeding arteries, surgical resection, electrothrombosis, direct intralesional injection of sclerosing agents, and endovascular embolization. Endovascular intervention increasingly is utilized as a primary treatment or as a preoperative adjunct to surgery.^2,4 Large S-AVFs have a high risk for recurrence after treatment with endovascular embolization alone. In cases with intracranial communication, the intracranial component is treated first.²

This case emphasizes the importance of including S-AVFs on the dermatologic differential diagnosis of a scalp nodule, especially in patients with any history of intracranial AVF. A thorough history, detailed intake of potential signs and symptoms of AVF, and palpation for bruits is recommended as part of the surgical evaluation of a scalp nodule. Imaging of scalp nodules also should be considered for patients with any history of intracranial AVF; S-AVFs should be referred to neurosurgery or interventional neuroradiology for evaluation and possible treatment.

To the Editor:

A 71-year-old man presented with a nodule on the vertex of the scalp of 1 year’s duration. The lesion had become soft and tender during the week prior to presentation. He noted that he was experiencing headaches and a buzzing sound in his head. He denied all other neurologic symptoms. The patient was given amoxicillin from a primary care physician and was referred to our institution for evaluation of a presumed inflamed cyst.

The patient’s medical history included an intracranial arteriovenous fistula (AVF) treated with endovascular embolization 1 year prior to presentation, 2 substantial falls in childhood with head trauma and loss of consciousness, essential hypertension, and an aortic aneurysm. His medications included amlodipine, lisinopril, amoxicillin, a multivitamin, and grape seed extract.

Physical examination revealed a 2-cm, pink, somewhat rubbery, subcutaneous, nonmobile nodule on the vertex of the scalp (Figure 1). The lesion was not consistent with a common pilar cyst, and an excisional biopsy was performed to exclude malignancy. Upon superficial incision, the lesion bled moderately, and the procedure was immediately discontinued. Hemostasis was obtained, and the patient was sent for ultrasonography of the lesion.

The diagnosis of an S-AVF is confirmed with imaging studies. Doppler ultrasonography initially will help to detect that a lesion is vascular in nature. Intra-arterial digital subtraction angiography is the gold-standard imaging technique and is necessary to delineate the feeding arteries and the draining channels as well as possible communication with intracranial vasculature.^1,2 There is controversy regarding the appropriate treatment of S-AVFs.² Each S-AVF possesses unique anatomic features that dictate appropriate management. The prognosis for an S-AVF is extremely variable, and the decision to treat is based on the patient’s symptoms and risk for exsanguinating hemorrhage.^2,4 Neurosurgical approaches include ligation of the feeding arteries, surgical resection, electrothrombosis, direct intralesional injection of sclerosing agents, and endovascular embolization. Endovascular intervention increasingly is utilized as a primary treatment or as a preoperative adjunct to surgery.^2,4 Large S-AVFs have a high risk for recurrence after treatment with endovascular embolization alone. In cases with intracranial communication, the intracranial component is treated first.²

This case emphasizes the importance of including S-AVFs on the dermatologic differential diagnosis of a scalp nodule, especially in patients with any history of intracranial AVF. A thorough history, detailed intake of potential signs and symptoms of AVF, and palpation for bruits is recommended as part of the surgical evaluation of a scalp nodule. Imaging of scalp nodules also should be considered for patients with any history of intracranial AVF; S-AVFs should be referred to neurosurgery or interventional neuroradiology for evaluation and possible treatment.

The Diagnosis: Microvenular Hemangioma  

Microvenular hemangioma is an acquired benign vascular neoplasm that was described by Hunt et al¹ in 1991, though Bantel et al² reported a similar entity termed micropapillary angioma in 1989. Microvenular hemangioma typically presents as a solitary, slowly enlarging, red to violaceous, asymptomatic papule, plaque, or nodule measuring 5 to 20 mm in diameter. It usually is located on the trunk, arms, or legs of young adults without any gender predilection. Microvenular hemangioma is rare.³ The etiology has not been elucidated, though a relationship with hormonal factors such as pregnancy or hormonal contraceptives has been described.²  

Histopathologically, microvenular hemangioma has a characteristic morphology. It is comprised of a well-circumscribed collection of thin-walled blood vessels with narrow lumens (quiz image).⁴ The blood vessels tend to infiltrate the superficial and deep dermis and are surrounded by a collagenous or desmoplastic stroma. The endothelial cells are normal in size without atypia, mitotic figures, or pleomorphism. A mild lymphoplasmacytic inflammatory infiltrate sometimes is present. Microvenular hemangioma expresses many vascular markers confirming its endothelial origin, including CD34, CD31, WT1, factor VIII-related antigen, and von Willebrand factor.³ Moreover, WT1 staining suggests the lesion is a vascular proliferative growth, as it usually is negative in vascular malformations due to errors of endothelial development.⁵ In addition, it lacks expression of podoplanin (D2-40), which also supports a vascular as opposed to a lymphatic origin.⁴  

Cutaneous angiosarcoma is a rare and highly aggressive malignant neoplasm of the vascular endothelium with a predilection for the skin and superficial soft tissue. Clinical presentation is variable, as it can arise sporadically, commonly on the scalp and face of elderly patients, in areas of chronic radiation therapy, or in association with chronic lymphedema (Stewart-Treves syndrome).⁶ Sporadic neoplasms appear clinically as purpuric macules, plaques, or nodules and are more common in elderly men than women. They are aggressive tumors that tend to recur and metastasize despite aggressive therapy and therefore carry a poor prognosis.⁷ Histopathologically, well-differentiated tumors are characterized by irregular dissecting vessels lined with crowded inconspicuous endothelial cells (Figure 1). Cutaneous angiosarcoma is poorly circumscribed with marked cytologic atypia, and the vessels can take on a sinusoidal growth pattern.⁸ 

Kaposi sarcoma (KS) is a virally induced lymphoangioproliferative disease, with human herpesvirus 8 as the implicated agent. There are 4 principal clinical variants of KS: epidemic or AIDS-associated KS, endemic or African KS, KS due to iatrogenic immunosuppression, and Mediterranean or classic KS.⁹ Cutaneous lesions vary from pink patches to dark purple plaques or nodules that commonly occur on the lower legs¹⁰; however, the clinical appearance of KS varies depending on the clinical variant and stage. Histopathologically, early lesions of KS exhibit a superficial dermal proliferation of small angulated and jagged vessels that tend to separate into collagen bundles and are surrounded by a lymphoplasmacytic perivascular infiltrate. These native vascular structures often are surrounded by more ectatic neoplastic channels with plump endothelial cells, known as the promontory sign (Figure 2).¹¹ With more advanced lesions, the proliferation of slitlike vessels becomes more cellular and extends deeper into the dermis and subcutis. Although the histopathologic features vary with the stage of the lesion, they do not notably vary between clinical subtypes. 

Targetoid hemosiderotic hemangioma, also known as hobnail hemangioma, is a small, benign, vascular tumor that usually affects the trunk, arms, and legs in young to middle-aged adults without a gender predilection. Clinically, it appears as a small, solitary, red to purple papule or macule that typically is surrounded by a pale thin area and a peripheral ecchymotic ring, creating a targetoid appearance, thus the term targetoid hemosiderotic hemangioma.¹² Histopathologically, there is a prominent dermal vascular proliferation. In the papillary dermis, there are dilated superficial vessels lined with a single layer of endothelial cells characterized by a plump, hobnail-like appearance that protrude into the lumen (Figure 3). In the deeper dermis, the vascular spaces are angulated and slitlike and appear to dissect through collagen bundles. Hemosiderin, thrombi, extravasated erythrocytes, and a lymphocytic infiltrate also are often seen.¹³  

Tufted angioma is a rare benign vascular lesion that usually presents as an acquired lesion in children and young adults, though it may be congenital. It is commonly localized to the skin and subcutaneous tissues. Clinically, the lesions appear as red to purple patches and plaques that typically are located on the neck or trunk. More than 50% of cases present during the first year of life and slowly spread to involve large areas before stabilizing in size.¹⁴ Partial spontaneous regression may occur, but complete regression is rare.¹⁵ Lesions usually are asymptomatic but may be painful during periods of platelet trapping (Kasabach-Merritt phenomenon), which may develop in congenital cases. Tufted angioma is named for its characteristic histopathologic appearance, which consists of multiple discrete lobules or tufts of tightly packed capillaries in a cannonball-like appearance throughout the dermis and subcutis (Figure 4).^14,15  

The Diagnosis: Microvenular Hemangioma  

Microvenular hemangioma is an acquired benign vascular neoplasm that was described by Hunt et al¹ in 1991, though Bantel et al² reported a similar entity termed micropapillary angioma in 1989. Microvenular hemangioma typically presents as a solitary, slowly enlarging, red to violaceous, asymptomatic papule, plaque, or nodule measuring 5 to 20 mm in diameter. It usually is located on the trunk, arms, or legs of young adults without any gender predilection. Microvenular hemangioma is rare.³ The etiology has not been elucidated, though a relationship with hormonal factors such as pregnancy or hormonal contraceptives has been described.²  

Histopathologically, microvenular hemangioma has a characteristic morphology. It is comprised of a well-circumscribed collection of thin-walled blood vessels with narrow lumens (quiz image).⁴ The blood vessels tend to infiltrate the superficial and deep dermis and are surrounded by a collagenous or desmoplastic stroma. The endothelial cells are normal in size without atypia, mitotic figures, or pleomorphism. A mild lymphoplasmacytic inflammatory infiltrate sometimes is present. Microvenular hemangioma expresses many vascular markers confirming its endothelial origin, including CD34, CD31, WT1, factor VIII-related antigen, and von Willebrand factor.³ Moreover, WT1 staining suggests the lesion is a vascular proliferative growth, as it usually is negative in vascular malformations due to errors of endothelial development.⁵ In addition, it lacks expression of podoplanin (D2-40), which also supports a vascular as opposed to a lymphatic origin.⁴  

Cutaneous angiosarcoma is a rare and highly aggressive malignant neoplasm of the vascular endothelium with a predilection for the skin and superficial soft tissue. Clinical presentation is variable, as it can arise sporadically, commonly on the scalp and face of elderly patients, in areas of chronic radiation therapy, or in association with chronic lymphedema (Stewart-Treves syndrome).⁶ Sporadic neoplasms appear clinically as purpuric macules, plaques, or nodules and are more common in elderly men than women. They are aggressive tumors that tend to recur and metastasize despite aggressive therapy and therefore carry a poor prognosis.⁷ Histopathologically, well-differentiated tumors are characterized by irregular dissecting vessels lined with crowded inconspicuous endothelial cells (Figure 1). Cutaneous angiosarcoma is poorly circumscribed with marked cytologic atypia, and the vessels can take on a sinusoidal growth pattern.⁸ 

Kaposi sarcoma (KS) is a virally induced lymphoangioproliferative disease, with human herpesvirus 8 as the implicated agent. There are 4 principal clinical variants of KS: epidemic or AIDS-associated KS, endemic or African KS, KS due to iatrogenic immunosuppression, and Mediterranean or classic KS.⁹ Cutaneous lesions vary from pink patches to dark purple plaques or nodules that commonly occur on the lower legs¹⁰; however, the clinical appearance of KS varies depending on the clinical variant and stage. Histopathologically, early lesions of KS exhibit a superficial dermal proliferation of small angulated and jagged vessels that tend to separate into collagen bundles and are surrounded by a lymphoplasmacytic perivascular infiltrate. These native vascular structures often are surrounded by more ectatic neoplastic channels with plump endothelial cells, known as the promontory sign (Figure 2).¹¹ With more advanced lesions, the proliferation of slitlike vessels becomes more cellular and extends deeper into the dermis and subcutis. Although the histopathologic features vary with the stage of the lesion, they do not notably vary between clinical subtypes. 

Targetoid hemosiderotic hemangioma, also known as hobnail hemangioma, is a small, benign, vascular tumor that usually affects the trunk, arms, and legs in young to middle-aged adults without a gender predilection. Clinically, it appears as a small, solitary, red to purple papule or macule that typically is surrounded by a pale thin area and a peripheral ecchymotic ring, creating a targetoid appearance, thus the term targetoid hemosiderotic hemangioma.¹² Histopathologically, there is a prominent dermal vascular proliferation. In the papillary dermis, there are dilated superficial vessels lined with a single layer of endothelial cells characterized by a plump, hobnail-like appearance that protrude into the lumen (Figure 3). In the deeper dermis, the vascular spaces are angulated and slitlike and appear to dissect through collagen bundles. Hemosiderin, thrombi, extravasated erythrocytes, and a lymphocytic infiltrate also are often seen.¹³  

Tufted angioma is a rare benign vascular lesion that usually presents as an acquired lesion in children and young adults, though it may be congenital. It is commonly localized to the skin and subcutaneous tissues. Clinically, the lesions appear as red to purple patches and plaques that typically are located on the neck or trunk. More than 50% of cases present during the first year of life and slowly spread to involve large areas before stabilizing in size.¹⁴ Partial spontaneous regression may occur, but complete regression is rare.¹⁵ Lesions usually are asymptomatic but may be painful during periods of platelet trapping (Kasabach-Merritt phenomenon), which may develop in congenital cases. Tufted angioma is named for its characteristic histopathologic appearance, which consists of multiple discrete lobules or tufts of tightly packed capillaries in a cannonball-like appearance throughout the dermis and subcutis (Figure 4).^14,15  

The Diagnosis: Microvenular Hemangioma  

Microvenular hemangioma is an acquired benign vascular neoplasm that was described by Hunt et al¹ in 1991, though Bantel et al² reported a similar entity termed micropapillary angioma in 1989. Microvenular hemangioma typically presents as a solitary, slowly enlarging, red to violaceous, asymptomatic papule, plaque, or nodule measuring 5 to 20 mm in diameter. It usually is located on the trunk, arms, or legs of young adults without any gender predilection. Microvenular hemangioma is rare.³ The etiology has not been elucidated, though a relationship with hormonal factors such as pregnancy or hormonal contraceptives has been described.²  

Histopathologically, microvenular hemangioma has a characteristic morphology. It is comprised of a well-circumscribed collection of thin-walled blood vessels with narrow lumens (quiz image).⁴ The blood vessels tend to infiltrate the superficial and deep dermis and are surrounded by a collagenous or desmoplastic stroma. The endothelial cells are normal in size without atypia, mitotic figures, or pleomorphism. A mild lymphoplasmacytic inflammatory infiltrate sometimes is present. Microvenular hemangioma expresses many vascular markers confirming its endothelial origin, including CD34, CD31, WT1, factor VIII-related antigen, and von Willebrand factor.³ Moreover, WT1 staining suggests the lesion is a vascular proliferative growth, as it usually is negative in vascular malformations due to errors of endothelial development.⁵ In addition, it lacks expression of podoplanin (D2-40), which also supports a vascular as opposed to a lymphatic origin.⁴  

Cutaneous angiosarcoma is a rare and highly aggressive malignant neoplasm of the vascular endothelium with a predilection for the skin and superficial soft tissue. Clinical presentation is variable, as it can arise sporadically, commonly on the scalp and face of elderly patients, in areas of chronic radiation therapy, or in association with chronic lymphedema (Stewart-Treves syndrome).⁶ Sporadic neoplasms appear clinically as purpuric macules, plaques, or nodules and are more common in elderly men than women. They are aggressive tumors that tend to recur and metastasize despite aggressive therapy and therefore carry a poor prognosis.⁷ Histopathologically, well-differentiated tumors are characterized by irregular dissecting vessels lined with crowded inconspicuous endothelial cells (Figure 1). Cutaneous angiosarcoma is poorly circumscribed with marked cytologic atypia, and the vessels can take on a sinusoidal growth pattern.⁸ 

Kaposi sarcoma (KS) is a virally induced lymphoangioproliferative disease, with human herpesvirus 8 as the implicated agent. There are 4 principal clinical variants of KS: epidemic or AIDS-associated KS, endemic or African KS, KS due to iatrogenic immunosuppression, and Mediterranean or classic KS.⁹ Cutaneous lesions vary from pink patches to dark purple plaques or nodules that commonly occur on the lower legs¹⁰; however, the clinical appearance of KS varies depending on the clinical variant and stage. Histopathologically, early lesions of KS exhibit a superficial dermal proliferation of small angulated and jagged vessels that tend to separate into collagen bundles and are surrounded by a lymphoplasmacytic perivascular infiltrate. These native vascular structures often are surrounded by more ectatic neoplastic channels with plump endothelial cells, known as the promontory sign (Figure 2).¹¹ With more advanced lesions, the proliferation of slitlike vessels becomes more cellular and extends deeper into the dermis and subcutis. Although the histopathologic features vary with the stage of the lesion, they do not notably vary between clinical subtypes. 

Targetoid hemosiderotic hemangioma, also known as hobnail hemangioma, is a small, benign, vascular tumor that usually affects the trunk, arms, and legs in young to middle-aged adults without a gender predilection. Clinically, it appears as a small, solitary, red to purple papule or macule that typically is surrounded by a pale thin area and a peripheral ecchymotic ring, creating a targetoid appearance, thus the term targetoid hemosiderotic hemangioma.¹² Histopathologically, there is a prominent dermal vascular proliferation. In the papillary dermis, there are dilated superficial vessels lined with a single layer of endothelial cells characterized by a plump, hobnail-like appearance that protrude into the lumen (Figure 3). In the deeper dermis, the vascular spaces are angulated and slitlike and appear to dissect through collagen bundles. Hemosiderin, thrombi, extravasated erythrocytes, and a lymphocytic infiltrate also are often seen.¹³  

Tufted angioma is a rare benign vascular lesion that usually presents as an acquired lesion in children and young adults, though it may be congenital. It is commonly localized to the skin and subcutaneous tissues. Clinically, the lesions appear as red to purple patches and plaques that typically are located on the neck or trunk. More than 50% of cases present during the first year of life and slowly spread to involve large areas before stabilizing in size.¹⁴ Partial spontaneous regression may occur, but complete regression is rare.¹⁵ Lesions usually are asymptomatic but may be painful during periods of platelet trapping (Kasabach-Merritt phenomenon), which may develop in congenital cases. Tufted angioma is named for its characteristic histopathologic appearance, which consists of multiple discrete lobules or tufts of tightly packed capillaries in a cannonball-like appearance throughout the dermis and subcutis (Figure 4).^14,15  

Relapsing polychondritis (RP) is a recurrent inflammatory condition involving primarily cartilaginous structures. The disease, first described as a clinical entity in 1960 by Pearson et al,¹ is rare with an estimated incidence of 3.5 cases per 1 million individuals.² The pathogenesis of RP is widely accepted as being autoimmune in nature, largely due to the identification of circulating autoantibodies seen in the sera of patients with similar clinical pictures.³

Although in most patients the primary process involves inflammation of cartilage, a subset of patients experience involvement of noncartilaginous sites.⁴ The degree of systemic involvement varies from none to notable, affecting the cardiovascular and respiratory systems and potentially leading to life-threatening complications, including cardiac valve compromise and airway collapse. Relapsing polychondritis is considered to be a progressive disease with the ultimate potential to be life-threatening.⁵

Human immunodeficiency virus (HIV) infection leads to a profound state of immune dysregulation, affecting innate, adaptive, and natural killer components of the immune system.⁶ There is variability in the development of autoimmune disease in HIV patients depending on the stage of infection. The frequency of rheumatologic disease in HIV patients might be as high as 60%.⁶ Relapsing polychondritis is rare in patients with HIV.^7-9 Of 4 reported cases, 2 patients had other coexisting autoimmune disease—sarcoidosis and Behçet disease.^8,9

Case Report

A 36-year-old man presented to the clinic with a concern of recurrent ear pain and swelling of approximately 2 years’ duration. Onset was sudden without inciting event. Symptoms initially involved the right ear with eventual progression to both ears. Additional symptoms included an auditory perception of underwater submersion, intermittent vertigo, and 3 episodes of throat closure sensation.

The patient’s medical history was notable for asthma; gastritis; depression; and HIV infection, which was diagnosed 4 years earlier and adequately managed with highly active antiretroviral therapy. His family history was notable for systemic lupus erythematosus in his mother, maternal aunt, and maternal cousin.

At presentation, the patient’s CD4 count was 799 cells/mm³ with an undetectable viral load. Medications included abacavir-dolutegravir-lamivudine, hydroxyzine, meclizine, mometasone, and quetiapine. Physical examination showed erythema, swelling, and tenderness of the left and right auricles with sparing of the earlobe that was more noticeable on the left ear (Figure 1). Bacterial culture from the external auditory meatus was positive for methicillin-resistant Staphylococcus aureus. Biopsy revealed chronic inflammatory perichondritis with mild to moderate fibrosis and chronic lymphocytic inflammation at the dermal cartilaginous junction (Figure 2). A direct immunofluorescent biopsy was unremarkable, but subsequent type II collagen antibodies were positive (35.5 endotoxin units/mL [reference range, <20 endotoxin units/mL]).

Comment

Relapsing polychondritis is an uncommon progressive disease characterized by recurrent inflammatory insults to cartilaginous and proteoglycan-rich structures.⁴ The most consistent clinical features of RP are ear inflammation that involves the auricle and spares the lobe, nasal chondritis, and arthralgia.¹⁰ Laryngotracheal compromise may occur from tracheal cartilage inflammation. The involvement of these specific structures is due to commonality between their component collagens.⁵ Although any organ system can be affected, as many as 50% of patients have respiratory tract involvement, which may affect any portion of the respiratory tree.¹¹ If involving the larynx, this inflammation can lead to severe edema warranting intubation. Cardiovascular involvement is present in 24% to 52% of patients,¹⁰ which most commonly manifests as valvular impairment affecting the aortic valve more frequently than the mitral valve.⁵

Pathogenesis
Although the etiology of RP remains undetermined, multiple hypotheses have been proposed. One is that a certain subset of patients is predisposed to autoimmunity, and a secondary triggering event in the form of infection, malignancy, or medication catalyzes development of RP. A second hypothesis is that mechanical trauma to cartilage exposes the immune system to certain antigens that would have otherwise remained hidden, prompting autosensitization.^12,13

Regardless of cause, an autoimmune pathogenesis is favored based on the following observations: RP is frequently associated with other autoimmune diseases in the same patient, glucocorticosteroids and other immunosuppressive therapies are effective for treatment, and histopathologic findings include an infiltrate of CD4⁺ T lymphocytes with detection of immunoglobulins and plasma cells in different lesions.⁵ The detection of autoantibodies against collagen in the serum of patients with RP further supports an autoimmune pathogenesis.³ The earliest identified autoantibodies in patients with RP were against type II collagen. Subsequent studies have identified autoantibodies against type IV and type XI collagens as well as other cartilage-related proteins such as matrilin 1¹⁴ and cartilage oligomeric matrix proteins.¹⁵ Although circulating antibodies to type II collagen are present in a variable number of patients with the disease (30%–70%), levels likely correlate with disease activity and are highest at times of acute inflammation.³ Additionally, titers of type II collagen antibodies have been shown to decrease upon institution of immunosuppressive therapy.¹⁶

Although a humoral response dominates the picture of RP, there also is an associated T cell–mediated response.¹³ Histopathologically, biopsy of an active lesion of auricular cartilage shows a mixed inflammatory infiltrate composed primarily of lymphocytes, with variable numbers of polymorphonuclear cells, monocytes, and plasma cells. Loss of basophilia of the cartilage matrix can be observed, thought to be the result of proteoglycan depletion.¹³ Later, lesions classically display apoptosis of chondrocytes, focal calcification, or fibrosis.⁵

Diagnosis
Relapsing polychondritis acts classically as an autoimmune disease with a variable presentation, making diagnosis a challenge. Many sets of diagnostic criteria have been proposed. The most referenced remains the original criteria described by McAdam et al.¹⁷ In 2012, the Relapsing Polychondritis Disease Activity Index modified criteria set forth by Michet et al¹⁸ and might serve as the standard for diagnosis going forward.¹⁹

McAdam et al¹⁷ proposed that 3 of 6 clinical features are necessary for diagnosis: bilateral auricular chondritis, nonerosive seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation, respiratory tract chondritis, and audiovestibular damage. Michet et al¹⁸ proposed that 1 of 2 conditions are necessary for diagnosis of RP: (1) proven inflammation in 2 of 3 of the auricular, nasal, or laryngotracheal cartilages; or (2) proven inflammation in 1 of 3 of the auricular, nasal, or laryngotracheal cartilages, plus 2 other signs, including ocular inflammation, vestibular dysfunction, seronegative inflammatory arthritis, and hearing loss.

These criteria were proposed originally in 1976¹⁷ and modified in 1986.¹⁸ No further updates have been offered since then. As such, serologic findings, such as antibodies against type II collagen, are not included in the diagnostic criteria. Additionally, these antibodies are not specific for RP and can be seen in other conditions such as rheumatoid arthritis.²⁰

More recently, imaging analysis has been employed in conjunction with clinical and serologic data to diagnose the disease and evaluate its severity. The use of imaging modalities for these purposes is most beneficial in patients with notable disease and respiratory involvement.²¹

Although the clinical picture is typified by the classic findings described above, the clinician must be aware of more subtle clues to diagnosis,¹¹ which is of particular importance to the dermatologist because 35% of patients with RP alone will have skin manifestations that can precede onset of chondritis.¹⁰ Most commonly, dermatologic manifestations are nonspecific and can include nodules on the limbs, purpura, and urticarial lesions.²² Individual case reports have noted the coexistence of RP with erythema multiforme,¹⁸ erythema annulare centrifugum,²³ pyoderma gangrenosum,²⁴ and panniculitis,¹⁸ among other disorders.

Severe systemic involvement leads to increased mortality and warrants more aggressive treatment.²² Commonly used agents include the immunosuppressants cyclophosphamide, cyclosporine, and methotrexate. Tumor necrosis factor α inhibitors have been the most widely utilized immunomodulatory agent for treatment of RP.^25,26 Abatacept and rituximab also have been used with variable efficacy in patients with severe disease. Recently, the IL-6 receptor blocker tocilizumab has been used with some success.²⁷

Prognosis
The prognosis for patients with RP largely depends on the severity of disease and degree of internal involvement. With improved management, largely due to awareness and recognition of disease, the survival rate among RP patients has increased from 55% at 10 years to 94% at the end of 8 years.¹⁸ The main cause of death in RP patients is airway complications related to laryngotracheal involvement.¹⁰ The second most common cause of death is cardiovascular complications in which valvular disease predominates.⁵

Concomitant Illness
Thirty-five percent of RP patients have coexisting autoimmune disease, the most common being antineutrophil cytoplasmic antibody–associated vasculitis.^5,28 Although this association with autoimmune disease is well described, reports of RP occurring in other states of immune dysfunction are sparse. One case of RP has been reported in a child with common variable immunodeficiency thought to be related to underlying abnormal immune regulation and immunodeficiency.²⁹ Relapsing polychondritis has been described in 4 patients with HIV, 2 of whom had concomitant autoimmune disease.^7-9

Human immunodeficiency virus infection is a well-established cause of immune dysregulation and has variable association with autoimmunity. This variability depends largely on the stage of infection. When divided into stages, autoimmune diseases develop predominantly in stage I, during acute infection with an intact immune system; in stage III, with immunosuppression, a low CD4 count, and development of AIDS; and in stage IV, when the immune system is restored with the institution of highly active antiretroviral therapy.⁶ The interplay between HIV infection and development of autoimmune disease is complex, and pathogenesis remains speculative.

Conclusion

Our patient represents a case of RP in an HIV-positive patient. Additionally, our patient had no other identifiable autoimmune conditions but did have a strong family history of them. It is important for providers to be aware of the potential for development of RP as well as other autoimmune disease in the setting of HIV infection. The implications of a missed diagnosis could be dire because the disease course of RP is progressive and has the potential to decrease survival.

Relapsing polychondritis (RP) is a recurrent inflammatory condition involving primarily cartilaginous structures. The disease, first described as a clinical entity in 1960 by Pearson et al,¹ is rare with an estimated incidence of 3.5 cases per 1 million individuals.² The pathogenesis of RP is widely accepted as being autoimmune in nature, largely due to the identification of circulating autoantibodies seen in the sera of patients with similar clinical pictures.³

Although in most patients the primary process involves inflammation of cartilage, a subset of patients experience involvement of noncartilaginous sites.⁴ The degree of systemic involvement varies from none to notable, affecting the cardiovascular and respiratory systems and potentially leading to life-threatening complications, including cardiac valve compromise and airway collapse. Relapsing polychondritis is considered to be a progressive disease with the ultimate potential to be life-threatening.⁵

Human immunodeficiency virus (HIV) infection leads to a profound state of immune dysregulation, affecting innate, adaptive, and natural killer components of the immune system.⁶ There is variability in the development of autoimmune disease in HIV patients depending on the stage of infection. The frequency of rheumatologic disease in HIV patients might be as high as 60%.⁶ Relapsing polychondritis is rare in patients with HIV.^7-9 Of 4 reported cases, 2 patients had other coexisting autoimmune disease—sarcoidosis and Behçet disease.^8,9

Case Report

A 36-year-old man presented to the clinic with a concern of recurrent ear pain and swelling of approximately 2 years’ duration. Onset was sudden without inciting event. Symptoms initially involved the right ear with eventual progression to both ears. Additional symptoms included an auditory perception of underwater submersion, intermittent vertigo, and 3 episodes of throat closure sensation.

The patient’s medical history was notable for asthma; gastritis; depression; and HIV infection, which was diagnosed 4 years earlier and adequately managed with highly active antiretroviral therapy. His family history was notable for systemic lupus erythematosus in his mother, maternal aunt, and maternal cousin.

At presentation, the patient’s CD4 count was 799 cells/mm³ with an undetectable viral load. Medications included abacavir-dolutegravir-lamivudine, hydroxyzine, meclizine, mometasone, and quetiapine. Physical examination showed erythema, swelling, and tenderness of the left and right auricles with sparing of the earlobe that was more noticeable on the left ear (Figure 1). Bacterial culture from the external auditory meatus was positive for methicillin-resistant Staphylococcus aureus. Biopsy revealed chronic inflammatory perichondritis with mild to moderate fibrosis and chronic lymphocytic inflammation at the dermal cartilaginous junction (Figure 2). A direct immunofluorescent biopsy was unremarkable, but subsequent type II collagen antibodies were positive (35.5 endotoxin units/mL [reference range, <20 endotoxin units/mL]).

Comment

Relapsing polychondritis is an uncommon progressive disease characterized by recurrent inflammatory insults to cartilaginous and proteoglycan-rich structures.⁴ The most consistent clinical features of RP are ear inflammation that involves the auricle and spares the lobe, nasal chondritis, and arthralgia.¹⁰ Laryngotracheal compromise may occur from tracheal cartilage inflammation. The involvement of these specific structures is due to commonality between their component collagens.⁵ Although any organ system can be affected, as many as 50% of patients have respiratory tract involvement, which may affect any portion of the respiratory tree.¹¹ If involving the larynx, this inflammation can lead to severe edema warranting intubation. Cardiovascular involvement is present in 24% to 52% of patients,¹⁰ which most commonly manifests as valvular impairment affecting the aortic valve more frequently than the mitral valve.⁵

Pathogenesis
Although the etiology of RP remains undetermined, multiple hypotheses have been proposed. One is that a certain subset of patients is predisposed to autoimmunity, and a secondary triggering event in the form of infection, malignancy, or medication catalyzes development of RP. A second hypothesis is that mechanical trauma to cartilage exposes the immune system to certain antigens that would have otherwise remained hidden, prompting autosensitization.^12,13

Regardless of cause, an autoimmune pathogenesis is favored based on the following observations: RP is frequently associated with other autoimmune diseases in the same patient, glucocorticosteroids and other immunosuppressive therapies are effective for treatment, and histopathologic findings include an infiltrate of CD4⁺ T lymphocytes with detection of immunoglobulins and plasma cells in different lesions.⁵ The detection of autoantibodies against collagen in the serum of patients with RP further supports an autoimmune pathogenesis.³ The earliest identified autoantibodies in patients with RP were against type II collagen. Subsequent studies have identified autoantibodies against type IV and type XI collagens as well as other cartilage-related proteins such as matrilin 1¹⁴ and cartilage oligomeric matrix proteins.¹⁵ Although circulating antibodies to type II collagen are present in a variable number of patients with the disease (30%–70%), levels likely correlate with disease activity and are highest at times of acute inflammation.³ Additionally, titers of type II collagen antibodies have been shown to decrease upon institution of immunosuppressive therapy.¹⁶

Although a humoral response dominates the picture of RP, there also is an associated T cell–mediated response.¹³ Histopathologically, biopsy of an active lesion of auricular cartilage shows a mixed inflammatory infiltrate composed primarily of lymphocytes, with variable numbers of polymorphonuclear cells, monocytes, and plasma cells. Loss of basophilia of the cartilage matrix can be observed, thought to be the result of proteoglycan depletion.¹³ Later, lesions classically display apoptosis of chondrocytes, focal calcification, or fibrosis.⁵

Diagnosis
Relapsing polychondritis acts classically as an autoimmune disease with a variable presentation, making diagnosis a challenge. Many sets of diagnostic criteria have been proposed. The most referenced remains the original criteria described by McAdam et al.¹⁷ In 2012, the Relapsing Polychondritis Disease Activity Index modified criteria set forth by Michet et al¹⁸ and might serve as the standard for diagnosis going forward.¹⁹

McAdam et al¹⁷ proposed that 3 of 6 clinical features are necessary for diagnosis: bilateral auricular chondritis, nonerosive seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation, respiratory tract chondritis, and audiovestibular damage. Michet et al¹⁸ proposed that 1 of 2 conditions are necessary for diagnosis of RP: (1) proven inflammation in 2 of 3 of the auricular, nasal, or laryngotracheal cartilages; or (2) proven inflammation in 1 of 3 of the auricular, nasal, or laryngotracheal cartilages, plus 2 other signs, including ocular inflammation, vestibular dysfunction, seronegative inflammatory arthritis, and hearing loss.

These criteria were proposed originally in 1976¹⁷ and modified in 1986.¹⁸ No further updates have been offered since then. As such, serologic findings, such as antibodies against type II collagen, are not included in the diagnostic criteria. Additionally, these antibodies are not specific for RP and can be seen in other conditions such as rheumatoid arthritis.²⁰

More recently, imaging analysis has been employed in conjunction with clinical and serologic data to diagnose the disease and evaluate its severity. The use of imaging modalities for these purposes is most beneficial in patients with notable disease and respiratory involvement.²¹

Although the clinical picture is typified by the classic findings described above, the clinician must be aware of more subtle clues to diagnosis,¹¹ which is of particular importance to the dermatologist because 35% of patients with RP alone will have skin manifestations that can precede onset of chondritis.¹⁰ Most commonly, dermatologic manifestations are nonspecific and can include nodules on the limbs, purpura, and urticarial lesions.²² Individual case reports have noted the coexistence of RP with erythema multiforme,¹⁸ erythema annulare centrifugum,²³ pyoderma gangrenosum,²⁴ and panniculitis,¹⁸ among other disorders.

Severe systemic involvement leads to increased mortality and warrants more aggressive treatment.²² Commonly used agents include the immunosuppressants cyclophosphamide, cyclosporine, and methotrexate. Tumor necrosis factor α inhibitors have been the most widely utilized immunomodulatory agent for treatment of RP.^25,26 Abatacept and rituximab also have been used with variable efficacy in patients with severe disease. Recently, the IL-6 receptor blocker tocilizumab has been used with some success.²⁷

Prognosis
The prognosis for patients with RP largely depends on the severity of disease and degree of internal involvement. With improved management, largely due to awareness and recognition of disease, the survival rate among RP patients has increased from 55% at 10 years to 94% at the end of 8 years.¹⁸ The main cause of death in RP patients is airway complications related to laryngotracheal involvement.¹⁰ The second most common cause of death is cardiovascular complications in which valvular disease predominates.⁵

Concomitant Illness
Thirty-five percent of RP patients have coexisting autoimmune disease, the most common being antineutrophil cytoplasmic antibody–associated vasculitis.^5,28 Although this association with autoimmune disease is well described, reports of RP occurring in other states of immune dysfunction are sparse. One case of RP has been reported in a child with common variable immunodeficiency thought to be related to underlying abnormal immune regulation and immunodeficiency.²⁹ Relapsing polychondritis has been described in 4 patients with HIV, 2 of whom had concomitant autoimmune disease.^7-9

Human immunodeficiency virus infection is a well-established cause of immune dysregulation and has variable association with autoimmunity. This variability depends largely on the stage of infection. When divided into stages, autoimmune diseases develop predominantly in stage I, during acute infection with an intact immune system; in stage III, with immunosuppression, a low CD4 count, and development of AIDS; and in stage IV, when the immune system is restored with the institution of highly active antiretroviral therapy.⁶ The interplay between HIV infection and development of autoimmune disease is complex, and pathogenesis remains speculative.

Conclusion

Our patient represents a case of RP in an HIV-positive patient. Additionally, our patient had no other identifiable autoimmune conditions but did have a strong family history of them. It is important for providers to be aware of the potential for development of RP as well as other autoimmune disease in the setting of HIV infection. The implications of a missed diagnosis could be dire because the disease course of RP is progressive and has the potential to decrease survival.

Relapsing polychondritis (RP) is a recurrent inflammatory condition involving primarily cartilaginous structures. The disease, first described as a clinical entity in 1960 by Pearson et al,¹ is rare with an estimated incidence of 3.5 cases per 1 million individuals.² The pathogenesis of RP is widely accepted as being autoimmune in nature, largely due to the identification of circulating autoantibodies seen in the sera of patients with similar clinical pictures.³

Although in most patients the primary process involves inflammation of cartilage, a subset of patients experience involvement of noncartilaginous sites.⁴ The degree of systemic involvement varies from none to notable, affecting the cardiovascular and respiratory systems and potentially leading to life-threatening complications, including cardiac valve compromise and airway collapse. Relapsing polychondritis is considered to be a progressive disease with the ultimate potential to be life-threatening.⁵

Human immunodeficiency virus (HIV) infection leads to a profound state of immune dysregulation, affecting innate, adaptive, and natural killer components of the immune system.⁶ There is variability in the development of autoimmune disease in HIV patients depending on the stage of infection. The frequency of rheumatologic disease in HIV patients might be as high as 60%.⁶ Relapsing polychondritis is rare in patients with HIV.^7-9 Of 4 reported cases, 2 patients had other coexisting autoimmune disease—sarcoidosis and Behçet disease.^8,9

Case Report

A 36-year-old man presented to the clinic with a concern of recurrent ear pain and swelling of approximately 2 years’ duration. Onset was sudden without inciting event. Symptoms initially involved the right ear with eventual progression to both ears. Additional symptoms included an auditory perception of underwater submersion, intermittent vertigo, and 3 episodes of throat closure sensation.

The patient’s medical history was notable for asthma; gastritis; depression; and HIV infection, which was diagnosed 4 years earlier and adequately managed with highly active antiretroviral therapy. His family history was notable for systemic lupus erythematosus in his mother, maternal aunt, and maternal cousin.

At presentation, the patient’s CD4 count was 799 cells/mm³ with an undetectable viral load. Medications included abacavir-dolutegravir-lamivudine, hydroxyzine, meclizine, mometasone, and quetiapine. Physical examination showed erythema, swelling, and tenderness of the left and right auricles with sparing of the earlobe that was more noticeable on the left ear (Figure 1). Bacterial culture from the external auditory meatus was positive for methicillin-resistant Staphylococcus aureus. Biopsy revealed chronic inflammatory perichondritis with mild to moderate fibrosis and chronic lymphocytic inflammation at the dermal cartilaginous junction (Figure 2). A direct immunofluorescent biopsy was unremarkable, but subsequent type II collagen antibodies were positive (35.5 endotoxin units/mL [reference range, <20 endotoxin units/mL]).

Comment

Relapsing polychondritis is an uncommon progressive disease characterized by recurrent inflammatory insults to cartilaginous and proteoglycan-rich structures.⁴ The most consistent clinical features of RP are ear inflammation that involves the auricle and spares the lobe, nasal chondritis, and arthralgia.¹⁰ Laryngotracheal compromise may occur from tracheal cartilage inflammation. The involvement of these specific structures is due to commonality between their component collagens.⁵ Although any organ system can be affected, as many as 50% of patients have respiratory tract involvement, which may affect any portion of the respiratory tree.¹¹ If involving the larynx, this inflammation can lead to severe edema warranting intubation. Cardiovascular involvement is present in 24% to 52% of patients,¹⁰ which most commonly manifests as valvular impairment affecting the aortic valve more frequently than the mitral valve.⁵

Pathogenesis
Although the etiology of RP remains undetermined, multiple hypotheses have been proposed. One is that a certain subset of patients is predisposed to autoimmunity, and a secondary triggering event in the form of infection, malignancy, or medication catalyzes development of RP. A second hypothesis is that mechanical trauma to cartilage exposes the immune system to certain antigens that would have otherwise remained hidden, prompting autosensitization.^12,13

Regardless of cause, an autoimmune pathogenesis is favored based on the following observations: RP is frequently associated with other autoimmune diseases in the same patient, glucocorticosteroids and other immunosuppressive therapies are effective for treatment, and histopathologic findings include an infiltrate of CD4⁺ T lymphocytes with detection of immunoglobulins and plasma cells in different lesions.⁵ The detection of autoantibodies against collagen in the serum of patients with RP further supports an autoimmune pathogenesis.³ The earliest identified autoantibodies in patients with RP were against type II collagen. Subsequent studies have identified autoantibodies against type IV and type XI collagens as well as other cartilage-related proteins such as matrilin 1¹⁴ and cartilage oligomeric matrix proteins.¹⁵ Although circulating antibodies to type II collagen are present in a variable number of patients with the disease (30%–70%), levels likely correlate with disease activity and are highest at times of acute inflammation.³ Additionally, titers of type II collagen antibodies have been shown to decrease upon institution of immunosuppressive therapy.¹⁶

Although a humoral response dominates the picture of RP, there also is an associated T cell–mediated response.¹³ Histopathologically, biopsy of an active lesion of auricular cartilage shows a mixed inflammatory infiltrate composed primarily of lymphocytes, with variable numbers of polymorphonuclear cells, monocytes, and plasma cells. Loss of basophilia of the cartilage matrix can be observed, thought to be the result of proteoglycan depletion.¹³ Later, lesions classically display apoptosis of chondrocytes, focal calcification, or fibrosis.⁵

Diagnosis
Relapsing polychondritis acts classically as an autoimmune disease with a variable presentation, making diagnosis a challenge. Many sets of diagnostic criteria have been proposed. The most referenced remains the original criteria described by McAdam et al.¹⁷ In 2012, the Relapsing Polychondritis Disease Activity Index modified criteria set forth by Michet et al¹⁸ and might serve as the standard for diagnosis going forward.¹⁹

McAdam et al¹⁷ proposed that 3 of 6 clinical features are necessary for diagnosis: bilateral auricular chondritis, nonerosive seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation, respiratory tract chondritis, and audiovestibular damage. Michet et al¹⁸ proposed that 1 of 2 conditions are necessary for diagnosis of RP: (1) proven inflammation in 2 of 3 of the auricular, nasal, or laryngotracheal cartilages; or (2) proven inflammation in 1 of 3 of the auricular, nasal, or laryngotracheal cartilages, plus 2 other signs, including ocular inflammation, vestibular dysfunction, seronegative inflammatory arthritis, and hearing loss.

These criteria were proposed originally in 1976¹⁷ and modified in 1986.¹⁸ No further updates have been offered since then. As such, serologic findings, such as antibodies against type II collagen, are not included in the diagnostic criteria. Additionally, these antibodies are not specific for RP and can be seen in other conditions such as rheumatoid arthritis.²⁰

More recently, imaging analysis has been employed in conjunction with clinical and serologic data to diagnose the disease and evaluate its severity. The use of imaging modalities for these purposes is most beneficial in patients with notable disease and respiratory involvement.²¹

Although the clinical picture is typified by the classic findings described above, the clinician must be aware of more subtle clues to diagnosis,¹¹ which is of particular importance to the dermatologist because 35% of patients with RP alone will have skin manifestations that can precede onset of chondritis.¹⁰ Most commonly, dermatologic manifestations are nonspecific and can include nodules on the limbs, purpura, and urticarial lesions.²² Individual case reports have noted the coexistence of RP with erythema multiforme,¹⁸ erythema annulare centrifugum,²³ pyoderma gangrenosum,²⁴ and panniculitis,¹⁸ among other disorders.

Severe systemic involvement leads to increased mortality and warrants more aggressive treatment.²² Commonly used agents include the immunosuppressants cyclophosphamide, cyclosporine, and methotrexate. Tumor necrosis factor α inhibitors have been the most widely utilized immunomodulatory agent for treatment of RP.^25,26 Abatacept and rituximab also have been used with variable efficacy in patients with severe disease. Recently, the IL-6 receptor blocker tocilizumab has been used with some success.²⁷

Prognosis
The prognosis for patients with RP largely depends on the severity of disease and degree of internal involvement. With improved management, largely due to awareness and recognition of disease, the survival rate among RP patients has increased from 55% at 10 years to 94% at the end of 8 years.¹⁸ The main cause of death in RP patients is airway complications related to laryngotracheal involvement.¹⁰ The second most common cause of death is cardiovascular complications in which valvular disease predominates.⁵

Concomitant Illness
Thirty-five percent of RP patients have coexisting autoimmune disease, the most common being antineutrophil cytoplasmic antibody–associated vasculitis.^5,28 Although this association with autoimmune disease is well described, reports of RP occurring in other states of immune dysfunction are sparse. One case of RP has been reported in a child with common variable immunodeficiency thought to be related to underlying abnormal immune regulation and immunodeficiency.²⁹ Relapsing polychondritis has been described in 4 patients with HIV, 2 of whom had concomitant autoimmune disease.^7-9

Human immunodeficiency virus infection is a well-established cause of immune dysregulation and has variable association with autoimmunity. This variability depends largely on the stage of infection. When divided into stages, autoimmune diseases develop predominantly in stage I, during acute infection with an intact immune system; in stage III, with immunosuppression, a low CD4 count, and development of AIDS; and in stage IV, when the immune system is restored with the institution of highly active antiretroviral therapy.⁶ The interplay between HIV infection and development of autoimmune disease is complex, and pathogenesis remains speculative.

Conclusion

Our patient represents a case of RP in an HIV-positive patient. Additionally, our patient had no other identifiable autoimmune conditions but did have a strong family history of them. It is important for providers to be aware of the potential for development of RP as well as other autoimmune disease in the setting of HIV infection. The implications of a missed diagnosis could be dire because the disease course of RP is progressive and has the potential to decrease survival.

The Diagnosis: Solitary Fibrous Tumor

Solitary fibrous tumors (SFTs), as first described by Klemperer and Rabin1 in 1931, are relatively uncommon mesenchymal neoplasms that occur primarily in the pleura. This lesion is now known to affect many other extrathoracic sites, such as the liver, kidney, adrenal glands, thyroid, central nervous system, and soft tissue, with rare examples originating from the skin.² Okamura et al³ reported the first known case of cutaneous SFT in 1997, with most of the literature limited to case reports. Erdag et al² described one of the largest case series of primary cutaneous SFTs. These lesions can occur across a wide age range but tend to primarily affect middle-aged adults. Solitary fibrous tumors have been known to have no sex predilection; however, Erdag et al² found a male predominance with a male to female ratio of 4 to 1. 

Histopathologically, a cutaneous SFT is known to appear as a well-circumscribed nodular spindle cell proliferation arranged in interlacing fascicles with an abundant hyalinized collagen stroma (quiz image). Alternating hypocellular and hypercellular areas can be seen. Supporting vasculature often is relatively prominent, represented by angulated and branching staghorn blood vessels (Figure 1).² A common histopathologic finding of SFTs is a patternless pattern, which suggests that the tumor can have a variety of morphologic appearances (eg, storiform, fascicular, neural, herringbone growth patterns), making histologic diagnosis difficult (quiz image).⁴ Therefore, immunohistochemistry plays a large role in the diagnosis of this tumor. The most important positive markers include CD34, CD99, B-cell lymphoma 2 (BCL-2), and signal transducer and activator of transcription 6 (STAT6).⁵ Nuclear STAT6 staining is an immunomarker for NGFI-A binding protein 2 (NAB2)-STAT6 gene fusion, which is specific for SFT.^5,6 Vivero et al⁷ also reported glutamate receptor, inotropic, AMPA 2 (GRIA2) as a useful immunostain in SFT, though it is also expressed in dermatofibrosarcoma protuberans (DFSP). In this case, the clinical and histopathologic findings best supported a diagnosis of SFT. Some consider hemangiopericytomas to be examples of SFTs; however, true hemangiopericytomas lack the thick hyalinized collagen and hypercellular areas seen in SFT.

A cellular dermatofibroma generally presents as a single round, reddish brown papule or nodule approximately 0.5 to 1 cm in diameter that is firm to palpation with a central depression or dimple created over the lesion from the lateral pressure. Cellular dermatofibromas mostly occur in middle-aged adults, with the most common locations on the legs and on the sides of the trunk. They are thought to arise after injuries to the skin. On histopathologic examination, cellular dermatofibromas typically exhibit a proliferation of fibrohistiocytic cells with collagen trapping, often at the periphery of the tumor (Figure 2). Although cellular dermatofibromas appear clinically different than SFTs, they often mimic SFTs histopathologically. Immunostaining also can be helpful in differentiating cellular dermatofibromas in which cells stain positive for factor XIIIa. CD34 staining is negative.

Dermatofibrosarcoma protuberans usually appears as one or multiple firm, red to violaceous nodules or plaques. They most often occur on the trunk in middle-aged adults. Histopathologically, DFSP presents with a dense, hypercellular, spindle cell proliferation that demonstrates a typical storiform pattern. The tumor generally infiltrates into the deep dermis and subcutaneous adipose layer with characteristic adipocyte entrapment (Figure 3). Positive CD34 and negative factor XIIIa staining helps to differentiate DFSP from a cellular dermatofibroma. Immunohistochemically, it is more difficult to distinguish DFSP from SFT, as both are CD34⁺ spindle cell neoplasms that also stain positive for CD99 and BCL-2.² GRIA2 positivity also is seen in both SFT and DFSP.⁷ However, differentiation can be made on morphologic grounds alone, as DFSP has ill-defined tumor borders with adnexal and fat entrapment and SFT tends to be more circumscribed with prominent arborizing hyalinized vessels.⁸

Spindle cell lipoma (SCL) is an asymptomatic subcutaneous tumor commonly located on the back, neck, and shoulders in older patients, typically men. It often presents as a solitary lesion, though multiple lesions may occur. It is a well-circumscribed tumor of mature adipose tissue with areas of spindle cell proliferation and ropey collagen bundles (Figure 4). In early lesions, the spindle cell areas are myxoid with the presence of many mast cells.⁹ The spindle cells stain positive for CD34. Although spindle cell lipoma would be included in both the clinical and histopathologic differential diagnosis for SFT, its histopathologic features often are enough to differentiate SCL, which is highlighted by the aforementioned features as well as a relatively low cellularity and lack of ectatic vessels.⁸ However, discerning tumor variants, such as low-fat pseudoangiomatous SCL and lipomatous or myxoid SFT, might prove more challenging.

Nodular fasciitis typically presents as a rapidly growing subcutaneous nodule that may be tender. It is a benign reactive process usually affecting the arms and trunk of young to middle-aged adults, though it commonly involves the head and neck region in children.¹⁰ The tumor histopathologically appears as a well-circumscribed subcutaneous or fascial nodule with an angulated appearance. Spindle-shaped and stellate fibroblasts are loosely arranged in an edematous myxomatous stroma with a feathered appearance (Figure 5). Extravasated erythrocytes often are present. With time, collagen bundles become thicker and hyalinized. Immunohistochemical studies demonstrate positivity for vimentin, calponin, muscle-specific actin, and smooth muscle actin. Desmin, CD34, cytokeratin, and S-100 typically are negative.^10-12 Therefore, CD34 staining is one of the main differentiating factors between nodular fasciitis and SFTs.

The Diagnosis: Solitary Fibrous Tumor

Solitary fibrous tumors (SFTs), as first described by Klemperer and Rabin1 in 1931, are relatively uncommon mesenchymal neoplasms that occur primarily in the pleura. This lesion is now known to affect many other extrathoracic sites, such as the liver, kidney, adrenal glands, thyroid, central nervous system, and soft tissue, with rare examples originating from the skin.² Okamura et al³ reported the first known case of cutaneous SFT in 1997, with most of the literature limited to case reports. Erdag et al² described one of the largest case series of primary cutaneous SFTs. These lesions can occur across a wide age range but tend to primarily affect middle-aged adults. Solitary fibrous tumors have been known to have no sex predilection; however, Erdag et al² found a male predominance with a male to female ratio of 4 to 1. 

Histopathologically, a cutaneous SFT is known to appear as a well-circumscribed nodular spindle cell proliferation arranged in interlacing fascicles with an abundant hyalinized collagen stroma (quiz image). Alternating hypocellular and hypercellular areas can be seen. Supporting vasculature often is relatively prominent, represented by angulated and branching staghorn blood vessels (Figure 1).² A common histopathologic finding of SFTs is a patternless pattern, which suggests that the tumor can have a variety of morphologic appearances (eg, storiform, fascicular, neural, herringbone growth patterns), making histologic diagnosis difficult (quiz image).⁴ Therefore, immunohistochemistry plays a large role in the diagnosis of this tumor. The most important positive markers include CD34, CD99, B-cell lymphoma 2 (BCL-2), and signal transducer and activator of transcription 6 (STAT6).⁵ Nuclear STAT6 staining is an immunomarker for NGFI-A binding protein 2 (NAB2)-STAT6 gene fusion, which is specific for SFT.^5,6 Vivero et al⁷ also reported glutamate receptor, inotropic, AMPA 2 (GRIA2) as a useful immunostain in SFT, though it is also expressed in dermatofibrosarcoma protuberans (DFSP). In this case, the clinical and histopathologic findings best supported a diagnosis of SFT. Some consider hemangiopericytomas to be examples of SFTs; however, true hemangiopericytomas lack the thick hyalinized collagen and hypercellular areas seen in SFT.

A cellular dermatofibroma generally presents as a single round, reddish brown papule or nodule approximately 0.5 to 1 cm in diameter that is firm to palpation with a central depression or dimple created over the lesion from the lateral pressure. Cellular dermatofibromas mostly occur in middle-aged adults, with the most common locations on the legs and on the sides of the trunk. They are thought to arise after injuries to the skin. On histopathologic examination, cellular dermatofibromas typically exhibit a proliferation of fibrohistiocytic cells with collagen trapping, often at the periphery of the tumor (Figure 2). Although cellular dermatofibromas appear clinically different than SFTs, they often mimic SFTs histopathologically. Immunostaining also can be helpful in differentiating cellular dermatofibromas in which cells stain positive for factor XIIIa. CD34 staining is negative.

Dermatofibrosarcoma protuberans usually appears as one or multiple firm, red to violaceous nodules or plaques. They most often occur on the trunk in middle-aged adults. Histopathologically, DFSP presents with a dense, hypercellular, spindle cell proliferation that demonstrates a typical storiform pattern. The tumor generally infiltrates into the deep dermis and subcutaneous adipose layer with characteristic adipocyte entrapment (Figure 3). Positive CD34 and negative factor XIIIa staining helps to differentiate DFSP from a cellular dermatofibroma. Immunohistochemically, it is more difficult to distinguish DFSP from SFT, as both are CD34⁺ spindle cell neoplasms that also stain positive for CD99 and BCL-2.² GRIA2 positivity also is seen in both SFT and DFSP.⁷ However, differentiation can be made on morphologic grounds alone, as DFSP has ill-defined tumor borders with adnexal and fat entrapment and SFT tends to be more circumscribed with prominent arborizing hyalinized vessels.⁸

Spindle cell lipoma (SCL) is an asymptomatic subcutaneous tumor commonly located on the back, neck, and shoulders in older patients, typically men. It often presents as a solitary lesion, though multiple lesions may occur. It is a well-circumscribed tumor of mature adipose tissue with areas of spindle cell proliferation and ropey collagen bundles (Figure 4). In early lesions, the spindle cell areas are myxoid with the presence of many mast cells.⁹ The spindle cells stain positive for CD34. Although spindle cell lipoma would be included in both the clinical and histopathologic differential diagnosis for SFT, its histopathologic features often are enough to differentiate SCL, which is highlighted by the aforementioned features as well as a relatively low cellularity and lack of ectatic vessels.⁸ However, discerning tumor variants, such as low-fat pseudoangiomatous SCL and lipomatous or myxoid SFT, might prove more challenging.

Nodular fasciitis typically presents as a rapidly growing subcutaneous nodule that may be tender. It is a benign reactive process usually affecting the arms and trunk of young to middle-aged adults, though it commonly involves the head and neck region in children.¹⁰ The tumor histopathologically appears as a well-circumscribed subcutaneous or fascial nodule with an angulated appearance. Spindle-shaped and stellate fibroblasts are loosely arranged in an edematous myxomatous stroma with a feathered appearance (Figure 5). Extravasated erythrocytes often are present. With time, collagen bundles become thicker and hyalinized. Immunohistochemical studies demonstrate positivity for vimentin, calponin, muscle-specific actin, and smooth muscle actin. Desmin, CD34, cytokeratin, and S-100 typically are negative.^10-12 Therefore, CD34 staining is one of the main differentiating factors between nodular fasciitis and SFTs.

The Diagnosis: Solitary Fibrous Tumor

Solitary fibrous tumors (SFTs), as first described by Klemperer and Rabin1 in 1931, are relatively uncommon mesenchymal neoplasms that occur primarily in the pleura. This lesion is now known to affect many other extrathoracic sites, such as the liver, kidney, adrenal glands, thyroid, central nervous system, and soft tissue, with rare examples originating from the skin.² Okamura et al³ reported the first known case of cutaneous SFT in 1997, with most of the literature limited to case reports. Erdag et al² described one of the largest case series of primary cutaneous SFTs. These lesions can occur across a wide age range but tend to primarily affect middle-aged adults. Solitary fibrous tumors have been known to have no sex predilection; however, Erdag et al² found a male predominance with a male to female ratio of 4 to 1. 

Histopathologically, a cutaneous SFT is known to appear as a well-circumscribed nodular spindle cell proliferation arranged in interlacing fascicles with an abundant hyalinized collagen stroma (quiz image). Alternating hypocellular and hypercellular areas can be seen. Supporting vasculature often is relatively prominent, represented by angulated and branching staghorn blood vessels (Figure 1).² A common histopathologic finding of SFTs is a patternless pattern, which suggests that the tumor can have a variety of morphologic appearances (eg, storiform, fascicular, neural, herringbone growth patterns), making histologic diagnosis difficult (quiz image).⁴ Therefore, immunohistochemistry plays a large role in the diagnosis of this tumor. The most important positive markers include CD34, CD99, B-cell lymphoma 2 (BCL-2), and signal transducer and activator of transcription 6 (STAT6).⁵ Nuclear STAT6 staining is an immunomarker for NGFI-A binding protein 2 (NAB2)-STAT6 gene fusion, which is specific for SFT.^5,6 Vivero et al⁷ also reported glutamate receptor, inotropic, AMPA 2 (GRIA2) as a useful immunostain in SFT, though it is also expressed in dermatofibrosarcoma protuberans (DFSP). In this case, the clinical and histopathologic findings best supported a diagnosis of SFT. Some consider hemangiopericytomas to be examples of SFTs; however, true hemangiopericytomas lack the thick hyalinized collagen and hypercellular areas seen in SFT.

A cellular dermatofibroma generally presents as a single round, reddish brown papule or nodule approximately 0.5 to 1 cm in diameter that is firm to palpation with a central depression or dimple created over the lesion from the lateral pressure. Cellular dermatofibromas mostly occur in middle-aged adults, with the most common locations on the legs and on the sides of the trunk. They are thought to arise after injuries to the skin. On histopathologic examination, cellular dermatofibromas typically exhibit a proliferation of fibrohistiocytic cells with collagen trapping, often at the periphery of the tumor (Figure 2). Although cellular dermatofibromas appear clinically different than SFTs, they often mimic SFTs histopathologically. Immunostaining also can be helpful in differentiating cellular dermatofibromas in which cells stain positive for factor XIIIa. CD34 staining is negative.

Dermatofibrosarcoma protuberans usually appears as one or multiple firm, red to violaceous nodules or plaques. They most often occur on the trunk in middle-aged adults. Histopathologically, DFSP presents with a dense, hypercellular, spindle cell proliferation that demonstrates a typical storiform pattern. The tumor generally infiltrates into the deep dermis and subcutaneous adipose layer with characteristic adipocyte entrapment (Figure 3). Positive CD34 and negative factor XIIIa staining helps to differentiate DFSP from a cellular dermatofibroma. Immunohistochemically, it is more difficult to distinguish DFSP from SFT, as both are CD34⁺ spindle cell neoplasms that also stain positive for CD99 and BCL-2.² GRIA2 positivity also is seen in both SFT and DFSP.⁷ However, differentiation can be made on morphologic grounds alone, as DFSP has ill-defined tumor borders with adnexal and fat entrapment and SFT tends to be more circumscribed with prominent arborizing hyalinized vessels.⁸

Spindle cell lipoma (SCL) is an asymptomatic subcutaneous tumor commonly located on the back, neck, and shoulders in older patients, typically men. It often presents as a solitary lesion, though multiple lesions may occur. It is a well-circumscribed tumor of mature adipose tissue with areas of spindle cell proliferation and ropey collagen bundles (Figure 4). In early lesions, the spindle cell areas are myxoid with the presence of many mast cells.⁹ The spindle cells stain positive for CD34. Although spindle cell lipoma would be included in both the clinical and histopathologic differential diagnosis for SFT, its histopathologic features often are enough to differentiate SCL, which is highlighted by the aforementioned features as well as a relatively low cellularity and lack of ectatic vessels.⁸ However, discerning tumor variants, such as low-fat pseudoangiomatous SCL and lipomatous or myxoid SFT, might prove more challenging.

Nodular fasciitis typically presents as a rapidly growing subcutaneous nodule that may be tender. It is a benign reactive process usually affecting the arms and trunk of young to middle-aged adults, though it commonly involves the head and neck region in children.¹⁰ The tumor histopathologically appears as a well-circumscribed subcutaneous or fascial nodule with an angulated appearance. Spindle-shaped and stellate fibroblasts are loosely arranged in an edematous myxomatous stroma with a feathered appearance (Figure 5). Extravasated erythrocytes often are present. With time, collagen bundles become thicker and hyalinized. Immunohistochemical studies demonstrate positivity for vimentin, calponin, muscle-specific actin, and smooth muscle actin. Desmin, CD34, cytokeratin, and S-100 typically are negative.^10-12 Therefore, CD34 staining is one of the main differentiating factors between nodular fasciitis and SFTs.