Histopathological and ultra structural studies of ovine pulmonary adenocarcinoma (Jaagsiekte)

Abstract

The Ovine Pulmonary adenocarcinoma (OPA) is also known as Jaagsiekte, is a contagious transmissible lung tumor of sheep caused by Jaagsiekte Sheep Retrovirus (JSRV). In the present study, 3698 lungs collected from slaughtered sheep in and around Tirupati, AP, India and examined morphologically. 396 lungs were showed different pneumonic lesions. Among 396 lung lesions 39 (9.85%) were diagnosed as Pulmonary adenocarcinoma. Grossly, all the lungs congested, increase in size, weight and oedematous. Consistency varied from granular to meaty appearance and many of them revealed nodules ranging from very small to 2.5 cm in diameter and serous exudate on cut surface of lung. Histologically, Papillary projections of epithelium into either alveolar or bronchiolar lumen. Intra alveolar fibrosis was prominent in many cases. Alveolar macrophages were consistently found within alveolar spaces. OPA also associated with different types of pneumonias. Ultrastructurally, proliferation of type II pneumocytes (Type B cells) having microvilli and well developed junctional complexes. Non ciliated bronchiolar epithelial cells (Clara cells) with electron dense cytoplasmic granules without any surrounding membrane and microvilli and no virus particles were traced.