Understanding of capillary malformation characteristics continue to evolve

INDIANAPOLIS – The way Maria C. Garzon, MD, sees it, capillary malformations are often misunderstood. She views them not as a single diagnosis but rather as a variety of conditions that fall under the term capillary malformation.

“The challenge is, we also use that term to describe a diagnosis,” Dr. Garzon, professor of dermatology and pediatrics at Columbia University, New York, said at the annual meeting of the Society for Pediatric Dermatology. “We have imperfect terminology. We use many different terms like capillary nevi and vascular stain. Instead of port wine stain, we now use the term port wine birthmark, and old terms like nevus flammeus are still used. This leads to diagnostic confusion, and it’s a barrier to developing care guidelines.”

Some capillary malformations, she noted, are benign and fade away while others can cause disfigurement or herald significant medical issues.

Histologically, she continued, not all capillary malformations are composed of capillaries. “Some are composed of postcapillary venules,” she said. “There are also mixed type capillary malformations that include lymphatic tissue, and the capillary malformation of capillary malformation-arteriovenous malformation (CM-AVM) syndrome shares histologic features of evolving AVMs as opposed to classic port wine birthmarks.”

The most recent International Society for the Study of Vascular Anomalies Classification of Vascular Anomalies was published in 2018 and is currently being updated. Other proposed clinical classifications have been published, including one that is diagnosis-specific and includes 20 different types of capillary malformations (J Eur Acad Dermatol Venereol. 2015 29[12]:2295-305, Pediatr Dermatol. 2016;33[6]:570-84).

“There are also syndromic classifications. Another question relates to the role of genomics: Are we ready for a classification that’s based purely on genetic variants, or do we need to incorporate it into existing classifications?” Dr. Garzon said. “Novel testing technologies using cell-free DNA and digital droplet PCR may be used in the future to establish diagnoses.” Genetic variants are found within capillary malformations, and they tend to be associated with three major pathways: the RAS-MAPK/ERK pathway, the PI3K/Akt/mTOR pathway, and the G protein pathway.

The type of capillary malformation that dermatologists and pediatricians most commonly see is nevus simplex, which occurs in 20%-82% of neonates. Other terms used include angel’s kiss, stork bite, salmon patch, nevus flammeus simplex, fading vascular stain, medial telangiectatic nevus, and butterfly mark. “It’s important to differentiate this from a port wine birthmark,” Dr. Garzon said. “This can be challenging when the birthmark is a darker red color. I have cared for patients who were initially thought to have nevus simplex and later found to have Sturge-Weber syndrome.”

Typical locations of nevus simplex include the central forehead/glabella, eyelids, the nape of the neck, scalp (parietal and occipital), nose, lip area (including philtrum), and the back (lumbosacral area and upper back). Most lesions fade/disappear without treatment (J Am Acad Dermatol. 2020;63[5]:805-14). Rare genetic syndromes associated with exaggerated nevus simplex complex include macrocephaly-capillary malformation syndrome and Beckwith-Wiedemann syndrome, “which tells us that this is a heterogeneous group of patients,” she said.

Dr. Garzon added that it’s “incredibly common” to see an eczema flare occurring within a nevus simplex on the nape of the neck. These patients will have a patch of atopic dermatitis that doesn’t get better. “Beneath it is their nevus simplex,” she said. “Remind parents that even after treating the eczema, the pink patch is not going to go away” (Pediatr Rep. 2021;13[1]:131-4).

Meanwhile, the classic port wine birthmark is usually congenital, uniform, and darker red in color. It darkens with maturity and the pattern will correlate with embryonic vasculature. “I am very wary of acquired port wine lesions,” she added. “It’s been described with trauma-related lesions, but early morphea can also mimic a port wine birthmark. You will see this if you’re practicing pediatric dermatology.”

Nearly a decade ago researchers established a link between port wine birthmarks and genetic variants in the GNAQ gene. “We see this in GNA11 as well,” Dr. Garzon said. “These changes are found in isolated port wine stains, and in Sturge-Weber syndrome. We now know that GNAQ drives the formation of large blood vessels through angiopoietin-2,” she noted (Arterioscler Throm Vasc Biol. 2022;42[1]:e27-43).

In general, studies that have examined genotype-phenotype correlations have demonstrated that the classic port wine birthmark is associated with GNAQ while GNA11 variants can be associated with a more reticulated pattern. “But this is not as clearcut as it seems,” she said. Investigators of a recent study showed an association between hypertension and renal anomalies in patients with skin capillary malformations and mosaic GNAQ or GNA11 variants. “This is a new finding,” she said. “Investigators are working to understand this association.”

Port wine birthmarks with the highest risk of Sturge-Weber syndrome include those that involve the forehead, upper eyelid, the midline frontonasal area, the hemifacial area, and median sites. “Patients who have this should be evaluated at birth,” Dr. Garzon said. “You should not delay for 2 months. They should be evaluated by ophthalmology and neurology early.”

The other morphologies commonly seen are “geographic” well-demarcated capillary malformations, which are dark in color. These lesions can be seen in conditions that are associated with genetic variants in PIK3CA (PROS) and include classic Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular malformations, epidermal nevi, scoliosis/skeletal and spinal) syndrome, and CLAPO (capillary malformation of the lower lip, lymphatic malformation of the face and neck, asymmetry of the face and limbs, and partial or generalized overgrowth) syndrome.

“Reticulated stains are much more heterogeneous,” Dr. Garzon said. “They can be localized or widespread. When you see a patient with a widespread reticulated capillary malformation, think about diffuse capillary malformation with overgrowth (DCMO). This condition is clinically and genetically heterogenous with the affected tissue of some patients showing variants in GNA11 while others have variants in PIK3CA. Therefore, a thorough examination at presentation and long-term follow-up is very important.”

Dr. Garzon disclosed that she is a member of the executive board for the International Society for the Study of Vascular Anomalies.

INDIANAPOLIS – The way Maria C. Garzon, MD, sees it, capillary malformations are often misunderstood. She views them not as a single diagnosis but rather as a variety of conditions that fall under the term capillary malformation.

“The challenge is, we also use that term to describe a diagnosis,” Dr. Garzon, professor of dermatology and pediatrics at Columbia University, New York, said at the annual meeting of the Society for Pediatric Dermatology. “We have imperfect terminology. We use many different terms like capillary nevi and vascular stain. Instead of port wine stain, we now use the term port wine birthmark, and old terms like nevus flammeus are still used. This leads to diagnostic confusion, and it’s a barrier to developing care guidelines.”

Some capillary malformations, she noted, are benign and fade away while others can cause disfigurement or herald significant medical issues.

Histologically, she continued, not all capillary malformations are composed of capillaries. “Some are composed of postcapillary venules,” she said. “There are also mixed type capillary malformations that include lymphatic tissue, and the capillary malformation of capillary malformation-arteriovenous malformation (CM-AVM) syndrome shares histologic features of evolving AVMs as opposed to classic port wine birthmarks.”

The most recent International Society for the Study of Vascular Anomalies Classification of Vascular Anomalies was published in 2018 and is currently being updated. Other proposed clinical classifications have been published, including one that is diagnosis-specific and includes 20 different types of capillary malformations (J Eur Acad Dermatol Venereol. 2015 29[12]:2295-305, Pediatr Dermatol. 2016;33[6]:570-84).

“There are also syndromic classifications. Another question relates to the role of genomics: Are we ready for a classification that’s based purely on genetic variants, or do we need to incorporate it into existing classifications?” Dr. Garzon said. “Novel testing technologies using cell-free DNA and digital droplet PCR may be used in the future to establish diagnoses.” Genetic variants are found within capillary malformations, and they tend to be associated with three major pathways: the RAS-MAPK/ERK pathway, the PI3K/Akt/mTOR pathway, and the G protein pathway.

The type of capillary malformation that dermatologists and pediatricians most commonly see is nevus simplex, which occurs in 20%-82% of neonates. Other terms used include angel’s kiss, stork bite, salmon patch, nevus flammeus simplex, fading vascular stain, medial telangiectatic nevus, and butterfly mark. “It’s important to differentiate this from a port wine birthmark,” Dr. Garzon said. “This can be challenging when the birthmark is a darker red color. I have cared for patients who were initially thought to have nevus simplex and later found to have Sturge-Weber syndrome.”

Typical locations of nevus simplex include the central forehead/glabella, eyelids, the nape of the neck, scalp (parietal and occipital), nose, lip area (including philtrum), and the back (lumbosacral area and upper back). Most lesions fade/disappear without treatment (J Am Acad Dermatol. 2020;63[5]:805-14). Rare genetic syndromes associated with exaggerated nevus simplex complex include macrocephaly-capillary malformation syndrome and Beckwith-Wiedemann syndrome, “which tells us that this is a heterogeneous group of patients,” she said.

Dr. Garzon added that it’s “incredibly common” to see an eczema flare occurring within a nevus simplex on the nape of the neck. These patients will have a patch of atopic dermatitis that doesn’t get better. “Beneath it is their nevus simplex,” she said. “Remind parents that even after treating the eczema, the pink patch is not going to go away” (Pediatr Rep. 2021;13[1]:131-4).

Meanwhile, the classic port wine birthmark is usually congenital, uniform, and darker red in color. It darkens with maturity and the pattern will correlate with embryonic vasculature. “I am very wary of acquired port wine lesions,” she added. “It’s been described with trauma-related lesions, but early morphea can also mimic a port wine birthmark. You will see this if you’re practicing pediatric dermatology.”

Nearly a decade ago researchers established a link between port wine birthmarks and genetic variants in the GNAQ gene. “We see this in GNA11 as well,” Dr. Garzon said. “These changes are found in isolated port wine stains, and in Sturge-Weber syndrome. We now know that GNAQ drives the formation of large blood vessels through angiopoietin-2,” she noted (Arterioscler Throm Vasc Biol. 2022;42[1]:e27-43).

In general, studies that have examined genotype-phenotype correlations have demonstrated that the classic port wine birthmark is associated with GNAQ while GNA11 variants can be associated with a more reticulated pattern. “But this is not as clearcut as it seems,” she said. Investigators of a recent study showed an association between hypertension and renal anomalies in patients with skin capillary malformations and mosaic GNAQ or GNA11 variants. “This is a new finding,” she said. “Investigators are working to understand this association.”

Port wine birthmarks with the highest risk of Sturge-Weber syndrome include those that involve the forehead, upper eyelid, the midline frontonasal area, the hemifacial area, and median sites. “Patients who have this should be evaluated at birth,” Dr. Garzon said. “You should not delay for 2 months. They should be evaluated by ophthalmology and neurology early.”

The other morphologies commonly seen are “geographic” well-demarcated capillary malformations, which are dark in color. These lesions can be seen in conditions that are associated with genetic variants in PIK3CA (PROS) and include classic Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular malformations, epidermal nevi, scoliosis/skeletal and spinal) syndrome, and CLAPO (capillary malformation of the lower lip, lymphatic malformation of the face and neck, asymmetry of the face and limbs, and partial or generalized overgrowth) syndrome.

“Reticulated stains are much more heterogeneous,” Dr. Garzon said. “They can be localized or widespread. When you see a patient with a widespread reticulated capillary malformation, think about diffuse capillary malformation with overgrowth (DCMO). This condition is clinically and genetically heterogenous with the affected tissue of some patients showing variants in GNA11 while others have variants in PIK3CA. Therefore, a thorough examination at presentation and long-term follow-up is very important.”

Dr. Garzon disclosed that she is a member of the executive board for the International Society for the Study of Vascular Anomalies.

INDIANAPOLIS – The way Maria C. Garzon, MD, sees it, capillary malformations are often misunderstood. She views them not as a single diagnosis but rather as a variety of conditions that fall under the term capillary malformation.

“The challenge is, we also use that term to describe a diagnosis,” Dr. Garzon, professor of dermatology and pediatrics at Columbia University, New York, said at the annual meeting of the Society for Pediatric Dermatology. “We have imperfect terminology. We use many different terms like capillary nevi and vascular stain. Instead of port wine stain, we now use the term port wine birthmark, and old terms like nevus flammeus are still used. This leads to diagnostic confusion, and it’s a barrier to developing care guidelines.”

Some capillary malformations, she noted, are benign and fade away while others can cause disfigurement or herald significant medical issues.

Histologically, she continued, not all capillary malformations are composed of capillaries. “Some are composed of postcapillary venules,” she said. “There are also mixed type capillary malformations that include lymphatic tissue, and the capillary malformation of capillary malformation-arteriovenous malformation (CM-AVM) syndrome shares histologic features of evolving AVMs as opposed to classic port wine birthmarks.”

The most recent International Society for the Study of Vascular Anomalies Classification of Vascular Anomalies was published in 2018 and is currently being updated. Other proposed clinical classifications have been published, including one that is diagnosis-specific and includes 20 different types of capillary malformations (J Eur Acad Dermatol Venereol. 2015 29[12]:2295-305, Pediatr Dermatol. 2016;33[6]:570-84).

“There are also syndromic classifications. Another question relates to the role of genomics: Are we ready for a classification that’s based purely on genetic variants, or do we need to incorporate it into existing classifications?” Dr. Garzon said. “Novel testing technologies using cell-free DNA and digital droplet PCR may be used in the future to establish diagnoses.” Genetic variants are found within capillary malformations, and they tend to be associated with three major pathways: the RAS-MAPK/ERK pathway, the PI3K/Akt/mTOR pathway, and the G protein pathway.

The type of capillary malformation that dermatologists and pediatricians most commonly see is nevus simplex, which occurs in 20%-82% of neonates. Other terms used include angel’s kiss, stork bite, salmon patch, nevus flammeus simplex, fading vascular stain, medial telangiectatic nevus, and butterfly mark. “It’s important to differentiate this from a port wine birthmark,” Dr. Garzon said. “This can be challenging when the birthmark is a darker red color. I have cared for patients who were initially thought to have nevus simplex and later found to have Sturge-Weber syndrome.”

Typical locations of nevus simplex include the central forehead/glabella, eyelids, the nape of the neck, scalp (parietal and occipital), nose, lip area (including philtrum), and the back (lumbosacral area and upper back). Most lesions fade/disappear without treatment (J Am Acad Dermatol. 2020;63[5]:805-14). Rare genetic syndromes associated with exaggerated nevus simplex complex include macrocephaly-capillary malformation syndrome and Beckwith-Wiedemann syndrome, “which tells us that this is a heterogeneous group of patients,” she said.

Dr. Garzon added that it’s “incredibly common” to see an eczema flare occurring within a nevus simplex on the nape of the neck. These patients will have a patch of atopic dermatitis that doesn’t get better. “Beneath it is their nevus simplex,” she said. “Remind parents that even after treating the eczema, the pink patch is not going to go away” (Pediatr Rep. 2021;13[1]:131-4).

Meanwhile, the classic port wine birthmark is usually congenital, uniform, and darker red in color. It darkens with maturity and the pattern will correlate with embryonic vasculature. “I am very wary of acquired port wine lesions,” she added. “It’s been described with trauma-related lesions, but early morphea can also mimic a port wine birthmark. You will see this if you’re practicing pediatric dermatology.”

Nearly a decade ago researchers established a link between port wine birthmarks and genetic variants in the GNAQ gene. “We see this in GNA11 as well,” Dr. Garzon said. “These changes are found in isolated port wine stains, and in Sturge-Weber syndrome. We now know that GNAQ drives the formation of large blood vessels through angiopoietin-2,” she noted (Arterioscler Throm Vasc Biol. 2022;42[1]:e27-43).

In general, studies that have examined genotype-phenotype correlations have demonstrated that the classic port wine birthmark is associated with GNAQ while GNA11 variants can be associated with a more reticulated pattern. “But this is not as clearcut as it seems,” she said. Investigators of a recent study showed an association between hypertension and renal anomalies in patients with skin capillary malformations and mosaic GNAQ or GNA11 variants. “This is a new finding,” she said. “Investigators are working to understand this association.”

Port wine birthmarks with the highest risk of Sturge-Weber syndrome include those that involve the forehead, upper eyelid, the midline frontonasal area, the hemifacial area, and median sites. “Patients who have this should be evaluated at birth,” Dr. Garzon said. “You should not delay for 2 months. They should be evaluated by ophthalmology and neurology early.”

The other morphologies commonly seen are “geographic” well-demarcated capillary malformations, which are dark in color. These lesions can be seen in conditions that are associated with genetic variants in PIK3CA (PROS) and include classic Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular malformations, epidermal nevi, scoliosis/skeletal and spinal) syndrome, and CLAPO (capillary malformation of the lower lip, lymphatic malformation of the face and neck, asymmetry of the face and limbs, and partial or generalized overgrowth) syndrome.

“Reticulated stains are much more heterogeneous,” Dr. Garzon said. “They can be localized or widespread. When you see a patient with a widespread reticulated capillary malformation, think about diffuse capillary malformation with overgrowth (DCMO). This condition is clinically and genetically heterogenous with the affected tissue of some patients showing variants in GNA11 while others have variants in PIK3CA. Therefore, a thorough examination at presentation and long-term follow-up is very important.”

Dr. Garzon disclosed that she is a member of the executive board for the International Society for the Study of Vascular Anomalies.