TRIPHASIC NEPHROBLASTOMA IN A HORSE

A large abdominal mass in a 3-year-old filly was discovered clinically and removed and examined after the horse had been humanely killed. Hi stologically, three different tissue types were noted, occurring in eq ual amounts: epithelium largely in the form of well-differentiated tub ules, multifocally distributed cell-dense foci of blastema, and myxoid to fibrous stroma. A diagnosis of triphasic nephroblastoma, a rare tu mour in the horse, was made on the basis of microscopical findings. Th e finding of numerous glomeruloid structures confirmed the diagnosis a nd assisted in distinguishing the tumour from a teratoma. The histogen esis of nephroblastoma is briefly discussed in the context of the hist ological and immunohistochemical findings of the case. (C) 1996 W.B. S aunders Company Limited