Abstract

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare cutaneous adnexal carcinoma with neuroendocrine differentiation which typically occurs in eyelids or adjacent areas of elderly individuals. It affects mostly female patients (F:M 2:1). EMPSGC for the most part exhibits an indolent clinical behavior and low metastatic potential. Herein, we report 3 cases of EMPSGC. The first case involved the chin of a 58-year-old male, the second case is a 52 year old male with a lesion of the righ lower eyelid and the third case is a 65 year old female with a lesion on the scalp. Histologically, all 3 cases showed dermal based, well-circumscribed multinodular neoplasms. The neoplastic cells were monomorphous, columnar or cuboidal with round to oval hyperchromatic nuclei and ample eosinophilic cytoplasm. They are arranged in cribriform, cystic, papillary or pseudorosette patterns. Delicate papillary fronds with fibrovascular cores are identified in some areas. In one of the cases, the cribriform areas showed mucin and calcifications in the cystic or gland-like spaces. Large mucinous lakes with floating small aggregates or cords of neoplastic cells were identified in two of the cases, consistent with components of invasive mucinous carcinoma. Immunohistochemical studies revealed the neoplastic cells to be strongly and diffusely positive for estrogen receptor, progesterone receptor, and GATA3, with a subset of cells positive for Synaptophysin. They are negative for CD117, TTF-1, Napsin A, CK20, CDX2, and SATB2. Epithelial-myoepithelial cocktail demonstrated the epithelial nature of the neoplastic cells with loss of myoepithelial cells at the periphery. These cases substantiate the proposal that EMPSGC may be a precursor or early stage in the evolution of cutaneous mucinous carcinoma with neuroendocrine differentiation. Although cutaneous mucinous carcinoma is a low grade carcinoma with few metastasis, close clinical monitoring and long term follow-up are warranted.

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