Canine dermal neoplasms: Evaluation of tumour proliferative fraction

Out of 105 cases 42 (40%) were skin tumours, among them 23 (54.8%) were benign and 19 (45.2%) malignant in nature. Tumours were recorded in an average age group of 7.27 years. Benign tumours were canine cutaneous histiocytoma (23.8%), cavernous hemangioma (7.1%), mast cell tumour (7.1%), perianal gland adenoma (7.1%), fibroma (4.8%) and fibromyxoma (4.8%). The malignant were basal cell carcinoma (19.0%), squamous cell carcinoma (7.1%), fibrosarcoma (4.8%), myxosarcoma (4.8%), perianal gland adenocarcinoma (4.8%), epidermoid carcinoma (2.4%) and liposarcoma (2.4%). There was significant correlation between four cell proliferative markers viz, mitotic index, AgNOR count, PCNA and Ki-67 indices (P<0.01). Protein Ki-67 proved to be very sensitive followed by PCNA in differentiating and determining the malignant tumours. Even though AgNOR count and mitotic index differed between malignant and benign tumours, alone they served as poor makers in providing additional objective support for the histological grading of tumours.