Sebaceous carcinoma arising from nevus sebaceus: a case report.

Background: Sebaceous carcinoma (SC) is a rare, aggressive, malignant tumor that is derived from adnexal epithelium of sebaceous glands that are distributed mostly in the skin of the head, neck, and hair-bearing regions of the body.
Objective: To discuss the clinical and histologic features and the prognosis of the extraocular SC.
Method: We report a case of SCs of the scalp arising from a previous lesion clinically compatible with a nevus sebaceous. The lesion was surgically excised completely.
Results: The postoperative course was free of complications, and the patient was clinically free of disease at her recent follow-up 2 years after treatment.
Conclusions: The absence of metastasis or cutaneous recurrence in our patient, notwithstanding the size of the lesion and its late removal, almost 25 years after the first signs of its growth, confirms a much improved prognostic behavior for extraocular SCs.