Multiple benign adnexal tumours: Anything but benign.

Area of Science:

• Oncology
• Genetics
• Dermatology

Background:

• Muir Torre syndrome is an autosomal dominant disorder linked to DNA mismatch repair gene mutations.
• It predisposes individuals to microsatellite instability and tumor formation, particularly sebaceous neoplasms and visceral malignancies.

Observation:

• A 67-year-old male presented with a nasal tip sebaceous adenoma.
• Immunohistochemistry revealed a loss of MSH6 expression.
• Genetic analysis identified a germline mutation consistent with Muir Torre syndrome.

Findings:

• The patient was diagnosed with Muir Torre syndrome following the identification of a sebaceous adenoma and a poorly differentiated adenocarcinoma.
• Loss of MSH6 staining was observed in both the cutaneous and visceral neoplasms.
• A germline mutation in a mismatch repair gene confirmed the diagnosis.

Implications:

• This case highlights the importance of considering Muir Torre syndrome in patients with cutaneous sebaceous neoplasms.
• Early screening for visceral malignancies in individuals with sebaceous neoplasms is crucial for timely diagnosis and treatment.
• The authors advocate for Muir Torre syndrome screening upon detection of cutaneous sebaceous neoplasms, even without a prior cancer history.