Multiple cellular neurothekeomas--a case report and review on the role of immunohistochemistry as a histologic adjunct.

Cellular neurothekeoma is a relatively rare, benign cutaneous neoplasm, which usually presents as a solitary papule or nodule involving the head and neck area of young adults. Multiple neurothekeomas have not, to date, been known to occur. We report a 30-year-old, otherwise healthy, male who presented with multiple neurothekeomas (15) in the head and neck area over a period of 12 years. While the unifying feature of all biopsied (10 of 15) lesions was the presence of epithelioid cells--the lesions differed in their cellularity and the degree of sclerosis of the stromal component. Antigenic profiling of the lesional cells revealed expression of vimentin, NKI/C3, PGP 9.5, factor XIIIa and CD68 but not S100, HMB45, MelanA, EMA, MSA, desmin, CD57 or NGF-R. This case report is the first to document the occurrence of multiple cellular neurothekeomas. An unusual histologic feature of some of the biopsied lesions was the presence of a markedly sclerotic stroma.