Abstract
BACKGROUND: Muir-Torre syndrome is a rare disorder characterized by patients suffering from sebaceous gland tumors or keratoacanthoma and visceral malignancies. More cases have been reported in Europe than in Asia. In this study, we report a case of MTS in China. CASE PRESENTATION: A 64 -year-old woman presented with a growth on the left upper eyelid noticed 3 months prior. Ancillary examinations include orbital CT, Ultrasound of parotid and submandibular glands, and Ultrasound of the cervical lymph nodes. All showed no clear abnormalities. Eyelid tumors were removed after general anesthesia. Seven months after the operation, a malignant rectal tumor was found. Based on the patient's clinical manifestations, physical signs, and ancillary test findings, this case was ultimately diagnosed as a rare presentation of keratoacanthoma combined with rectal malignancy. CONCLUSIONS: This case report describes a rare occurrence of Muir-Torre syndrome (MTS) diagnosed in a patient who presented with a keratoacanthoma of the eyelid and subsequently developed rectal carcinoma. The diagnosis was confirmed through comprehensive clinical evaluation and molecular analysis demonstrating microsatellite instability, consistent with the diagnostic criteria for MTS.