Abstract

Background: Muir Torre syndrome (MTS) is a rare genetic disorder. MTS is caused by mutations in genes that regulate cell growth and division. Specifically, it is linked to mutations in the DNA mismatch repair system. MTS increases the risk of developing skin and gastrointestinal tumors such as sebaceous adenomas, sebaceous carcinomas, colorectal cancer, endometrial cancer, and ovarian cancer. The risk of developing these types of tumors varies depending on the involved mutation and the individual's family history.

Case Presentation: A 47-year-old gentleman presented with multiple skin lesions on his scalp, face, flank, and back. The examination revealed well-circumscribed, dome-shaped papules with a yellowish appearance with white oily material in the center. Histopathological examination showed focal cystic changes and peritumoral lymphocytic infiltrate consistent with sebaceous adenomas. MMR staining showed preserved expression in MLH1 and PMS2, while MSH2 and MSH6 staining showed loss of protein expression. A screening colonoscopy showed numerous colon and rectal tumors, prompting concerns about the likelihood of Muir-Torre syndrome. Surgical intervention was necessary, leading to the resection of the tumors, which were found to be mucinous adenocarcinoma/adenocarcinoma with mucinous features in the colon. The diagnosis of MTS was supported by MSH2 germline mutation. The increased likelihood of MTS was attributed to the occurrence of sebaceous adenomas in unusual locations of the head and neck regions, unlike typical cases.

Conclusion: MTS is a unique condition that necessitates continuous surveillance. When sebaceous adenoma arises in atypical regions, it is important to consider additional screening to eliminate the likelihood of MTS.