Immunohistochemical detection of JSRV capsid protein in sheep affected with ovine pulmonary adenocarcinoma

Ovine pulmonary adenocarcinoma is a potential malignant tumour of sheep caused by Jaagsiekte sheep retro virus (JSRV). Lungs and mediastinal lymph nodes collected from 17 OPA affected sheep from local slaughter houses were used for gross, histopathology and immunohistochemical studies. Grossly, lungs revealed diffuse areas of consolidation. Histologically, the lung sections revealed non encapsulated neoplastic areas of alveolar epithelial cells in papillary or acinar pattern along with bronchiolar epithelial cell hyperplasia. Myxomatous nodules of various sizes were present in the tumour stroma and around the adjacent bronchioles.In three cases metastasis of lung tumour into mediastinal lymph nodes was observed. Immunostaining for JSRV-Capsid Antigen showed strong positive reaction in all the neoplastic cells, alveolar macrophages and in the metastatic epithelial cells of the lymph nodes.