Indian Journal of Veterinary Pathology

The present study was designed to characterize and diagnose different spontaneously occurring canine neoplasms using conventional and advanced diagnostic techniques. Fifty eight tumour samples were collected from dogs irrespective of their sex, breed, age and were grouped in three categories viz. mammary, skin and visceral tumours. Location wise overall occurrence of tumours was highest in skin (50%) followed by visceral organs (25.86%) and mammary gland (24.13%). Cytological diagnosis from 30 freshly incised tissues revealed 14 benign and 16 malignant cases. Histopathological diagnosis (n=58) evinced 1 (1.72%) benign mammary tumour (carcinoma-in situ); 13 (22.41%) malignant mammary tumours (mixed carcinoma-4, tubular carcinoma-4, tub- ulopapillary carcinoma-3, comedocarcinoma-1 and poorly differentiated carcinoma-1); 12 (20.68%) benign skin tumours (perianal gland adenoma-5, trichoblastoma-4, trich of olliculoma-1, tricholemmoma-1 and haemangioma-1); 17 (29.31%) malignant skin tumours (fibrosarcoma-6, mast cell tumour-3, apocrine adenocarcinoma-3, haemangiopericytoma-1, perianal gland adenocarcinoma-1, chondrosarcoma-1, melanoma-1, poorly differentiated carcinoma-1); 9 (15.51%) benign visceral tumours (oral papilloma-4, sertoli cell tumour-1, angioleiomyoma-1, ceruminous gland adenoma-1, ameloblastic fibro-odontoma-1, haemangioma-1); and 6 (10.34%) malignant visceral tumours (haemangiosarcoma-4, round cell sarcoma-1 and vaginal haemangiopericytoma-1). Immunohistochemistry was performed in 30 tumours for various molecular markers, viz. F8, SMA, Desmin, S-100, HER2 and ER. All mammary tumours were found negative for ER and HER2, whereas fibrosarcoma and haemangiosarcoma were found positive for SMA and F8, respectively. Real time PCR was employed to study the overexpression of ERBB2 gene in tumour tissues. Over expression of ERB-B2 was found only in skin fibrosarcoma (10 fold) and apocrine adenocarcinoma (112 fold).