Sebaceous Nevus: A clinicopathological study of 168 cases and review of the literature

Background:Sebaceous nevus (SN) is a hamartoma composed of abnormal epidermal and dermalcomponents with clinical and histopathological features that change with ageing.Prophylactic excision of the lesion was advised historically considering its potential forgiving rise to malignant tumors. However, whether early prophylactic excision should beperformed or not has been questioned recently since most of the originated tumors have beenfound to be of benign nature.Materials and Methods:The histopathologic features of 168 sebaceous nevi were reviewed to determine the frequencyof different histologic features as well as associated neoplastic growths.Results:Acanthosis, papillomatosis and basal layer pigmentation were the most frequent findings.Hyperplastic changes of the sebaceous glands became obvious during the second decade andwere present in 60% of the specimens from individuals older than 20. Inflammatory infiltratewas almost invariably present. Neoplastic changes were detected in 9 cases including 4trichoblastomas, 3 tricholemmomas and 2 syringocystadenoma papilliferums.Conclusion:Development of malignancies in sebaceous nevi is a rare phenomenon and decision forexcision of the lesion should be made after thorough evaluation of pros and cons.