GRANULAR-CELL TUMOR EXPRESSING MYOGENIC MARKERS IN THE PROSTATE

A granular cell tumor in the prostate of a 72 year old male is reporte d, The tumor nest was composed of large polygonal tumor cells, possess ing cytoplasmic eosinophilic granules which were positive with PAS sta in and resistant to diastase digestion. Immunohistochemically, most tu mor cells were strongly positive with anti-alpha-smooth muscle actin a nd -neuron specific enolase antibodies, Only a few scattered tumor cel ls were reacted with anti-S-100 protein antibody, These findings might suggest smooth muscle differentiation of this case, and provide an ad ditional insight into the histogenesis of granular cell tumors, especi ally in their heterogeneity.