Pathological and immunohistochemical evaluations of extra genital transmissible venereal tumour in dogs: a report of two cases Bahl Shreya1, Jangir Babu Lal1*, Narang Gulshan1, Sharma Satbir2, Chandratre Gauri A.1 1Department of Veterinary Pathology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar-125004, Haryana, India. 2Department of Veterinary Clinical Complex, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar-125004, Haryana, India. Dr. Babu Lal Jangir, Department of Veterinary Pathology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar-125004, Haryana, India, E-mail: drbabu.jangir@gmail.com
Abstract Transmissible venereal tumour (TVT) is a transplantable tumour of dogs with its primary site on external genitalia of either sex. However, extra genital TVT are less commonly noticed on skin and eyes. The present study describes the pathomorpho-logical features and expression of proliferating cell nuclear antigen (PCNA), Ki67 and cyclooxygenase-2 (COX-2) by immuno-histochemistry in primary extra genital TVTs in dogs located at ocular and thigh regions. The cytopathological examination of both cases revealed round cells with characteristic punctate cytoplasmic vacuoles, faint bluish cytoplasm and mitotic fi gures. Histopathologically, both the cases revealed islands of neoplastic cells with centrally placed round nuclei containing single nu-cleolus, abundant cytoplasm, separated by thin fi brous connective tissue strands and numerous mitotic fi gures. Mitotic count in ocular and thigh regions of TVT was 5.6/hpf and 6.2/hpf, respectively. AgNOR count/ nucleus in these cases was 1.21 and 1.1, respectively. PCNA and Ki67 immunostainings were observed in the nuclei of neoplastic cells. PCNA index in both cases was very high (84-85%). In ocular TVT, Ki67 immunostaining was mainly restricted to mitotic fi gures; however, TVT in thigh region revealed Ki67 reactivity in proliferating cells as well as mitotic fi gures. Mild COX-2 immunostaining was noticed in some tumour as well as in infl ammatory cells in TVT at thigh region, while no immunoreactivity was noticed in ocular TVT. In conclusion, both cases were diagnosed as TVT on the basis of cytopathological and histopathological features. The co-expression of PCNA and Ki67 indicated the high proliferative activity of neoplastic cells. Although, COX-2 expression was less and observed in only one case, but its signifi cance in such cases may be explored out by studying a large number of such cases. Top Keywords Cyclooxygenase-2, Extra genital, Ki67, Proliferating cell nuclear antigen, Transmissible venereal tumour. Top |