Pigmented Multinucleate Cell Angiohistiocytoma: First Case

Multinucleate cell angiohistiocytoma (MCAH) is a benign vascular and fibrohistiocytic (probably reactive) proliferation with peculiar multinucleate cells which most authors interpret as degenerated macrophages. Several clinical variants of MCAH have been described, some of them with brownish-appearing lesions clinically. However, no histologically identified pigment has been described in the cytoplasm of the multinucleate cells so far. We present a pigmented MCAH with cytoplasmic brownish pigment, which was positive with a Masson-Fontana stain and negative with an iron stain, consistent with melanin, in a 33-year-old woman with multiple papules and plaques on the right elbow, right jawline, and left flank.