Granular cell tumor in the central nervous system of a ferret (Mustela putorius furo)- a case report

A granular cell tumor (GCT) in the central nervous system (CNS) of a ferret is a rare finding. In this case a cerebral GCT is described in a 5-year-old castrated female ferret. The animal developed lameness in right hind leg which progreseed to total ataxia. The animal died and a necropsy revealed the mass in the medial to caudal part of the left frontal lobe of the brain. Based on histological and imunohistochemical findings, tumor was diagnosed as granular cell tumor. Immunohistochemically, granular cells were diffusely positive for vimentin and neuron-specific enolase (NSE) and weakly focal reactivity for S-100 protein was seen. Neoplastic cells did not express cytokeratins and glial fibrillary acidic protein (GFAP). Although immunohistochemistry was performed, histogenesis of this tumor remains unsolved and controversial.