Endocrine mucin-producing sweat gland carcinoma: Case report and literature review.

PurposeTo provide more basis for further diagnosis and differentiation for Endocrine Mucin-Producing Sweat Gland Carcinoma (EMPSGC), we offer a case report and a comprehensive review of the epidemiology, immunohistochemical findings, and molecular mechanisms underlying EMPSGC.Case descriptionWe herein present a case of a 70-year-old Chinese male patient who presented with a painless, progressively enlarging skin mass at his right lateral canthus. Histopathological examination revealed solid papillary growth patterns with intracellular mucin, and immunohistochemical staining was positive for Ki-67, P53, EMA, CK7, GATA3, CgA, Syn, INSM1, and AR, confirming the diagnosis of EMPSGC. Literature revealed that EMPSGC is a rare, low-grade malignant tumor with neuroendocrine differentiation. Key immunohistochemical markers include CK7, GATA-3, and INSM1, which aid in diagnosis. Hormone receptors such as ER, PgR, and AR are frequently expressed. The recurrence risk ranges from 7.11% to 14.3%, with rare cases of metastasis to the parotid gland, lungs, and skeletal system. Following surgical resection and subsequent pathological examination, the lesion was diagnosed as EMPSGC. In this report, we delineate the clinical presentation, Hematoxylin and eosin (H&E) staining features, and immunohistochemical characteristics of this case. We also conduct a literature review to enhance the understanding of EMPSGC.ConclusionEMPSGC is a relatively rare type of eyelid tumor in ophthalmic diagnosis and treatment. However, it poses a significant risk of misdiagnosis with other ocular tumors. Any eyelid mass demands attention, and necessitates prompt resection followed by intraoperative and/or postoperative pathological examination to avoid misdiagnose and poor prognosis.