A case of sebaceous carcinoma diagnosed in an adolescent male

Sebaceous carcinoma is an uncommon and potentially aggressive malignancy that exhibits sebaceous differentiation. Approximately 75% of cases arise in the periocular region. Sebaceous carcinoma is rare in the pediatric population and its presentation in this age group is not well documented in the dermatopathology literature. We report the case of a 15-year-old male with sebaceous carcinoma who was first seen with a nodular lesion involving the skin of the left orbit/temporal area. A shave biopsy was performed which showed an infiltrative proliferation of basaloid cells that focally exhibited sebaceous differentiation, including the formation of incipient sebocytes. Immunohistochemically, the tumor cells expressed epithelial membrane antigen (EMA) and CK5/6, while a lack of Ber-EP4 was observed. Based upon these attributes, the diagnosis of sebaceous carcinoma was rendered. Subsequent immunohistochemical analysis for a possible DNA mismatch repair enzyme defect revealed that all four mismatch repair gene products showed retained expression, thereby providing no support for the presence of underlying Muir-Torre syndrome. Sebaceous carcinomas are exceptional in the pediatric age group and are rarely documented in the dermatopathology literature. Knowledge that this adult carcinoma can occur mostly in the pediatric age group may aid in the recognition of this uncommon malignancy.