Type 2 segmental glomangiomas.

Glomangiomas of the skin, currently named glomuvenous malformations (GVMs), are benign vascular lesions composed of thin-walled distorted blood vessels, surrounded by variable rows of glomus cells. These cells resemble the modified smooth muscle cells of the normal glomus body. Glomuvenous malformations occur after both alleles of the gene encoding for glomulin, a molecule involved in smooth muscle cell differentiation, are hit by a loss-of-function mutation. Multiple GVMs are rare and often congenital, but they may also appear later in life. In this report we describe a 39-year-old man who developed unilateral segmental GVMs on his trunk in early childhood, with the histological features of glomangiomas. As several satellite lesions emerged at distant skin sites later in life, our case probably represents type 2 segmental GVMs, caused by localized loss of heterozygosity in an individual carrying a heterozygous germline mutation in the glomulin gene.