Eyelid, Endocrine mucin-producing sweat gland carcinoma, mucicarmine stain

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is an under-recognized low-grade carcinoma with predilection to the eyelid, presenting as a slowly growing cyst or swelling. Histologically, they are well circumscribed, and typically multinodular tumours with solid or partially cystic nodules. Focal cribriform arrangements can also be present. The cells are uniform, small to medium-sized, and oval to polygonal epithelial cells with lightly eosinophilic to bluish cytoplasm. The nuclei are bland with diffusely stippled chromatin. Intracytoplasmic and extracellular mucin are usually present. All tumours tested expressed estrogen and progesterone receptors, neuroendocrine markers cytokeratin 7, Cam5.2, and EMA. Mucicarmine highlights the mucin vacuoles.

Reference: Zembowicz A, et al. Endocrine mucin-producing sweat gland carcinoma: twelve new cases suggest that it is a precursor of some invasive mucinous carcinomas. Am J Surg Pathol. 2005;29:1330–1339

This slide shows mucicarmine stain. See Related Content for H&E, ER, and synaptophysin stains.