Malignant transformation of nevus sebaceous to basal-cell carcinoma: Case series, literature review, and management algorithm

Nevus sebaceous (NS) is a common congenital hamartoma of the skin composed predominantly of sebaceous glands. Although most NS are benign skin tumors, malignant transformations have been reported. There is still controversy about the lifetime risk of malignant degeneration and precise surgical criteria. This study reports cases of malignant degeneration and suggests a surgical treatment algorithm. The medical records of patients with basal-cell carcinoma (BCC) arising from NS between January 2001 and January 2021 were retrospectively reviewed. Patient demographics including lesion location, and tumor size were investigated. The symptoms, histological findings before and after excision, complications, and recurrence during 2-year follow-up periods were investigated. Ten patients were identified with BCC arising from NS lesions. All patients were female and the mean age was 52.11 years. All patients complained of sudden morphological changes, the most common type being rapid color changes. Two cases had histological findings that showed a miss-match between punch biopsy and excisional biopsy results. No recurrence was detected 2 years after surgeries in any patients. Cases after third stage, especially in over 40 years who report morphologic changes, should undergo total surgical excision as the first approach, with strong suspicion of malignant degeneration.