Multinucleate Cell Angiohistiocytoma: A Case Report

Multinucleate cell angiohistiocytoma (MCAH) is a rare skin lesion characterized by multiple papules, usually found on the extremities of middle-aged women. We report such a case in a 42-year- old woman who had noticed a gradually enlarging purpuric plaque and several brown-to-violet papules on her forehead for one year. A biopsy specimen of the plaque showed dermal vascular proliferation embedded in connective tissue containing a number of bizarre, multinucleated giant cells. Immunohistochemical study showed that the endothelial cells were positive for CD34, the multinucleate cells were positive only for vimentin, and the mononuclear interstitial cells were positive for CD68. A diagnosis of multinucleate cell angiohistiocytoma was made. We report this case and review the literature.