Multicentric Asynchronous Endocrine Mucin-Producing Sweat Gland Carcinoma and Mucinous Carcinoma of the Skin.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is an adnexal neoplasm which typically occurs on periorbital skin and demonstrates overlapping histopathologic features with primary mucinous carcinoma of the skin (MCS). Herein, we report a patient who developed five distinct lesions of EMPSGC and MCS over an eight-year period, some of which occurred on periorbital sites and others which occurred on the lower face. We further sought to better characterize these tumors on a molecular basis; targeted next generation sequencing analysis of two discrete tumors revealed identical missense variants within the ATRX gene. Our report expands on the rare prior reports of multicentric, asynchronous EMPSGC and MCS, and also provides a basis for additional genetic classification of these neoplasms.