Cellular Neurothekeoma of the Scalp in the Elderly.

Cellular neurothekeoma (CNT) is an uncommon variant of neurothekeoma that is composed of pithelioid to spindled cells with variable nuclear atypia or pleomorphism but no myxoid stroma. CNT occurs predominantly in the head and neck or upper trunk of children and young adults, with female predominance. The following case is different from typical CNTs. An 88-year-old female presented with a palpable mass on the scalp, which we excised. Histologically, the tumor was non-encapsulated and composed of spindled and epithelioid cells arranged in fascicles and nodules separated by a collagen-rich stroma. Immunohistochemical analysis showed that the epithelioid and spindle-shaped cells were focally positive for vimentin, neuron-specific enolase, smooth muscle actin, CD68, and CD10 but negative for S-100 protein, HMB-45, epithelial membrane antigen, and CD34. We report a new case of CNT that arose in the scalp of an older patient and that was associated with uncommon clinical, histological, and immunohistochemical profiles.