By Gary M. White, MD
Capillary Malformation-Arteriovenous Malformation (CM-AVM) combines multifocal congenital capillary malformations with arteriovenous malformations.
The CMs are congenital or acquired, round-to-oval, pink-to-red or brownish, small, capillary spots, often surrounded by a pale halo. There may be one or several lesions. They may be present at birth, but usually appear in early childhood. Some patients will have lesions characterized as small white pale halos with a central punctate red spot, and nevus anemicus. Hypotrichosis in the form of partial or total absence of vellus hair on the surface of CMs is frequent [British Journal of Dermatology, 172: 450–454]. The number of CMs has ranged from 1 to 60.
The AVMS occur in about 1/3 of patients and may occur anywhere, including superficial or deep structures such as skin, muscle, bone, spine and brain.
When the diagnosis is in question, evidence of RASA1 mutation or familial history of CMs or AVMs is supportive. Port-wine stain and Sturge–Weber syndrome are caused by mutations in GNAQ. Patients who are negative for the mutation probably have a yet unknown mutation of the RASA1 gene, because they and their family members also have a higher risk of high-flow arteriovenous malformations (present in up to 25% of cases).
CM and hypotrichosis British Journal of Dermatology, 172: 450–454
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