Background. Nevus sebaceus has a well-documented potential to develop a wide variety of neoplasms of both epidermal and adnexal origins. It is highly unusual for more than three tumors to arise simultaneously within a single nevus sebaceus. Sebaceous carcinoma arising within a nevus sebaceus is a rare occurrence.

Objective. The objective was to report the case of a patient with a nevus sebaceus that simultaneously developed five distinct neoplasms of epidermal and various adnexal origins and to report the fourth case of sebaceous carcinoma arising within a nevus sebaceus.

Methods. A 45-year-old woman presented with a nevus sebaceusthat contained five separate neoplasms, including sebaceous carcinoma, basal cell carcinoma, trichoadenoma, trichoblastoma, and syringocystadenoma papilliferum.

Results. Complete excision of the nevus sebaceus and the five tumors was performed. Systemic work-up showed no evidence of metastatic disease or association with Muir-Torre syndrome.

Conclusion. This case report highlights the diverse neoplastic potential of nevus sebaceus and demonstrates the capacity of this hamartoma to develop aggressive tumors, such as sebaceous carcinoma. Prophylactic excision or at least close clinical surveillance for sudden development of new growths is warranted in all cases of nevus sebaceus.