Abstract
PURPOSE: To report a rare case of endocrine mucin-producing sweat gland carcinoma (EMPSGC) of the eyelid, initially misdiagnosed as a chalazion. OBSERVATIONS: A 76-year-old South-Asian male presented with a 9-month history of a painless left upper eyelid lesion. Initial ophthalmic assessment suggested presence of a chalazion that did not resolve with medical management. Examination revealed a 5.5 × 5.5 mm mass at the central left eyelid margin. The lesion transilluminated and extended over the eyelid margin, with splayed lashes but no madarosis. Histopathological examination demonstrated cribriforming glandular epithelium with extracellular mucin and synaptophysin expression, confirming EMPSGC with associated mucinous carcinoma. The patient underwent successful Mohs micrographic surgery with oculoplastic reconstruction and with no evidence of recurrence at five-month follow-up. CONCLUSION AND IMPORTANCE: EMPSGC is an uncommon, low-grade adnexal neoplasm, often under-recognized due to its benign appearance. This case highlights the importance of considering EMPSGC in the differential diagnosis of persistent eyelid lesions, particularly those unresponsive to conservative treatment. Histopathologic evaluation is critical for early recognition and appropriate management of lesions.