[Psammomatous melanotic schwannoma].

Psammomatous melanotic schwannoma is a rare variant of schwannoma. The authors present histological and immunohistochemical findings in two cases of the tumor arising in the spinal nerve roots region at a 56-year-old woman and a 58-year-old man. The latter recurred locally. Microscopically the tumor was composed of polygonal epithelioid or spindle-shaped cells. Some of these cells contained melanin. Small calcifications were dispersed throughout the lesion. Ultrastructural examination of one of these cases revealed nerve sheath origin of the tumor cells and identified premelanosomes and melanosomes within the cytoplasm of neoplastic cells. Histogenesis and relationship of the tumor to Carney complex are discussed.