Osteoma Cutis Associated with Nevus Sebaceus: Case Report and Review of Cutaneous Osteoma-associated Skin Tumors (COASTs).

Osteoma cutis is a benign cutaneous lesion characterized by the presence of bone within the dermis or subcutaneous fat. It most often develops in association with other skin lesions such as cutaneous tumors. Nevus sebaceus is a benign hamartoma of the skin that is composed of epidermal and dermal components. It most commonly appears on the scalp and may give rise to either benign or malignant secondary neoplasms. The clinical and pathologic features of a 36-year-old man with a nevus sebaceus and associated osteoma cutis are described. In addition, osteoma cutis-associated neoplasms are reviewed. Secondary osteoma cutis has been observed with both benign and malignant neoplasms as well as various non-neoplastic skin conditions. However, to the best of our knowledge, osteoma cutis has not previously been described in association with nevus sebaceus. Nevus sebaceus can now be added to the list of cutaneous osteoma-associated skin tumors (COASTs).