Basal Cell Carcinoma on a Nevus Sebaceous of Jadassohn: A Case Report.

The nevus sebaceous of Jadassohn, usually present at birth, is a hamartoma composed predominantly of sebaceous glands, which can progress to benign and malignant tumors. Malignant neoplasms on the nevus sebaceous occur in about 2.5 percent of cases, with basal cell carcinoma accounting for 1.1 percent. Suspected cases of transformation should be clinically monitored and excised. We report the case of a 38-year-old man with a yellowish plaque located in the left parietal region, present from birth, on which a brownish papular lesion developed. The histopathological examination showed that it was a basal cell carcinoma. In presenting this case of basal cell carcinoma on a nevus sebaceous, we emphasize the evolutionary possibilities in order to improve prompt diagnosis and correct treatment.