Muir-Torre syndrome and recent updates on screening guidelines: The link between colorectal tumors and sebaceous adenomas in unusual locations

J Surg Oncol. 2023 Dec;128(8):1380-1384. doi: 10.1002/jso.27440. Epub 2023 Sep 14.


Background: Muir-Torre syndrome (MTS) is a rare genetic disorder that is caused by mismatch repair (MMR) protein mutations. MTS increases the risk of developing skin and gastrointestinal tumors such as sebaceous adenomas (SAs), 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 risk.

Case presentation: A 47-year-old male presented with multiple skin lesions on the scalp, face, flank, and back. The examination revealed well-circumscribed, dome-shaped papules with a yellowish appearance with white oily material in the center. Histopathologic examination showed a well-circumscribed sebaceous neoplasm consistent with a mixture of basaloid cells and lobules of bland-appearing mature adipocytes that communicate directly to the surface epithelium. Focal cystic changes and peritumoral lymphocytic infiltrate were noted. Increased mitotic figures were seen in the basaloid cell component. The overall findings were consistent with the diagnosis of SAs. MMR staining showed preserved expression in MLH1 and PMS2 proteins, 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 MTS. Surgical intervention was pursued for complete resection. Histology revealed a diagnosis of mucinous adenocarcinoma/adenocarcinoma with mucinous features of the colon. The diagnosis of MTS was supported by molecular testing that revealed MSH2 germline mutation. The increased likelihood of MTS was attributed to the occurrence of SAs in unusual locations of the head and neck regions, unlike typical cases.

Conclusion: MTS is a rare clinical condition that necessitates prompt thorough evaluation and periodic surveillance. When SA is encountered in atypical locations, it is important to consider additional testing supported by immunohistochemical staining, molecular testing, and regular screening to exclude the likelihood of MTS.

Keywords: Muir-Torre syndrome; colorectal tumors; sebaceous adenoma.

Publication types

  • Case Reports

MeSH terms

  • Adenoma* / diagnosis
  • Adenoma* / genetics
  • Adenoma* / pathology
  • Colorectal Neoplasms* / diagnosis
  • Colorectal Neoplasms* / genetics
  • Colorectal Neoplasms* / metabolism
  • Humans
  • Male
  • Middle Aged
  • Muir-Torre Syndrome* / diagnosis
  • Muir-Torre Syndrome* / genetics
  • Muir-Torre Syndrome* / pathology
  • MutS Homolog 2 Protein
  • Sebaceous Gland Neoplasms* / diagnosis
  • Sebaceous Gland Neoplasms* / genetics
  • Sebaceous Gland Neoplasms* / pathology


  • MutS Homolog 2 Protein

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