Immuno-histochemical study on a rare case of hepatic carcino-sarcoma in an Indian water buffalo (Bubalus bubalis)

A rare case of hepatic tumour from a buffalo having heterogeneous appearance of epithelial and mesenchymal component(s) in hepatic parenchyma with exhilarating metastasis to lungs is reported. The gross lesions includes distorted yellowish, white multiple thickened nodular mass of variable sizes, with minimal central necrotic areas either in liver and lungs. Histologically, spindle shaped cells within irregular fibrous trabaecular network, intermingled with scanty amount of epithelial or mesenchymal component(s) along with infiltration at tumour and non tumour boundary was observed. The tumour cells in liver reacted positively with pan-cytokeratin (pCK), polyclonal carcinoembryonic antigen (pCEA) and vimentin (VM), while focal positivity to cytokeratin 7 (CK7) in liver and locally scattered immunoreactivity to cytokeratin7 (CK7) in lungs was appreciated, which indicated the sarcomatoid transformation of carcinomatous feature of neoplasm in liver. Ki-67 immunostaining exhibited high proliferative index. The periodic acid Schiff (PAS) and Masson's Trichome staining exhibited the mucinous and fibrous contents of tumour respectively at different sites.