A 68-year-old man with a history of multiple non-melanoma skin cancers presented with a well-circumscribed, firm, pink-yellow lesion on the scalp. The lesion was biopsied and signed out as sebaceous carcinoma.
The correct answer is ...
It occurs most frequently in children and young adults.
Sebaceous carcinoma is a malignant neoplasm with sebaceous differentiation that typically presents as a tan-pink to yellow lesion around the eyelid. It usually arises in older adults; the median age at time of diagnosis is 73 years. While the periocular region is the most common site, sebaceous carcinoma can also occur at extra-ocular sites, as in this case.
Some sebaceous carcinomas are characterized by defective mismatch repair; most of these cases are somatic mutations, rather than germline. Patients with multiple sebaceous tumors, especially extraocular, should be assessed for Muir-Torre syndrome, which is characterized by germline mutations in mismatch repair genes MLH1, MSH2, MSH6, and PMS2. Muir-Torre syndrome is a variant of hereditary, non-polyposis colorectal cancer and confers an increased risk of colorectal carcinoma. Lastly, although not entirely specific, androgen receptor (AR) is often positively expressed in sebaceous tumors.
Amanda Nguyen, M.D.
Resident, Anatomic & Clinical Pathology
Ray Guo, M.D., Ph.D.
Consultant, Anatomic Pathology
Associate Professor of Laboratory Medicine and Pathology; Associate Professor of Dermatology
Mayo Clinic College of Medicine and Science