Cytological and histopathological characterization of squamous cell carcinoma from mammary region in a male dog : A case study

Cancer is a fatal malignant disturbance of growth and one of the major causes of morbidity and mortality among canines. Squamous cell carcinoma (SCC) is relatively more common and a highly malignant neoplasm, known to affect dogs. However, SCC of the mammary region is rare in occurrence in both veterinary and human medicine. The present study describes a case of well differentiated SCC of the mammary region in a male dog. An eleven-year-old intact male Pit Bull was presented in Veterinary Polyclinic Lalhri Distt Una, with a history of multiple cutaneous ulcerative lesions in the region of right posterior mammary gland. Fine needle aspiration and touch impression cytology smears were stained with giemsa examined on the day of presentation revealed large number of malignant squamous epithelial cells occurring either individually or in clusters exhibiting marked pleomorphism, anisocytosis and anisokaryosis suggestive of SCC. Surgical resection of the lesion involving mammary tissue was done. The excised mass grossly presented as grayish, irregular in size, lobulated subcutaneous tissue. The representative tissue pieces preserved in 10% neutral buffered formalin were subjected to histopathological evaluation. Histopathological examination revealed cords and nests of proliferating neoplastic cells in the dermis consisting of immature polyhedral cells at the periphery and eosinophilic laminated keratin pearls at the centre separated by thin fibrous tissue stroma confirmed it for well differentiated form of SCC. The diagnosis of a well differentiated SCC was made on the basis of cytological findings and further confirmed on histopathological evaluation besides special staining.