IMMUNOHISTOCHEMICAL EVALUATION OF CANINE PRIMARY LIVER CARCINOMAS - DISTRIBUTION OF ALPHA-FETOPROTEIN, CARCINOEMBRYONIC ANTIGEN, KERATINS AND VIMENTIN

The immunohistochemical expression of the oncofetal proteins alpha-fet oprotein (AFP) and carcinoembryonic antigen (CEA), and the intermediat e filament proteins keratin and vimentin was analysed in 18 canine liv er carcinomas. All the tumours other than hepatocellular carcinomas, w ith the exception of one poorly differentiated carcinoma, were AFP neg ative, and only cholangiocarcinomas and mixed (hepatocellular and chol angiocellular) carcinomas were CEA positive. All the histological type s of tumours expressed high and low molecular weight keratins, and ker atin and vimentin were both expressed in three tumours (one moderately differentiated hepatocellular carcinoma, one mixed carcinoma and one poorly differentiated carcinoma). The findings demonstrate the use of immunohistochemical staining methods for analysing the expression of s ome tumour markers in routinely processed tissue samples of canine liv er carcinomas, and suggest that some of the tumour markers are correla ted with histological types of tumour.