Microvenular hemangioma presenting with numerous bilateral macules, patches, and plaques: a case report and review of the literature.

Microvenular hemangioma (MVH) is a rare, slowly growing, benign vascular tumor that typically presents as a solitary enlarging plaque or nodule on the trunk or the extremities of young to middle-aged adults. A minority of MVH present with multiple lesions that are either gradually or suddenly acquired (eruptive MVH). Herein, we report a case of a 53-year-old woman who progressively developed numerous bilateral MVHs presenting as enlarging, blanching, erythematous to violaceous macules, patches, and plaques over the proximal thighs and axillae. Two biopsies exhibited the irregular branching venules with inconspicuous lumina lacking endothelial atypia and associated with dermal fibrosis characteristic of MVH. Immunophenotypically, the endothelium expressed Wilms Tumor 1, CD31, CD34, and erythrocyte-type glucose transporter protein (GLUT-1) GLUT-1 focally and was negative for Human herpes virus 8 and the lymphatic marker D2-40. In addition, numerous dermal spindle cells expressing CD34 and procollagen, putative fibrocytes, surrounded the thickened dermal collagen bundles and small vessels of MVH implicating a reactive/reparative (proliferative) process due to an unrecognized cutaneous injury. A review of MVH summarizing its clinicopathologic findings and its natural history is presented.