Pulmonary papillary adenocarcinoma in a slaughtered zobawng cattle

Lung cancer is one of the leading causes of cancer-related deaths worldwide. Prognosis for patients with lung cancer is generally poor. Primary lung tumors are rare in cattle, making their occurrence an uncommon finding in slaughterhouses. Papillary adenocarcinomas are typically highly malignant, often accompanied by intrapulmonary metastases in various lobes, bronchial lymph nodes, pleura, and even the brain. Here, we present a case of a 6-year-old male Zobawng cattle that was examined at the Government slaughterhouse in Mizoram. During the inspection of the carcass and visceral organs, a single whitish-grey nodular mass measuring approximately 5cm × 4cm was observed attached to the right lobe of the lungs in the mediastinal area. The nodular mass was preserved in 10% neutral buffered formalin (NBF) for fixation. After paraffin embedding, tissue sections were cut at a 4-5μ thickness, stained with hematoxylin and eosin (H and E), and examined microscopically. The neoplastic epithelial cells exhibited a tubular pattern with papillary projections extending into the tubular lumen. These cells displayed aggressive infiltrative growth into adjacent tissues, supported by a fine fibrovascular connective tissue stroma. The proliferating epithelial cells were markedly pleomorphic and anaplastic. Based on clinical, gross, and histopathological findings, the observed masses in the male Zobawng cattle were diagnosed as pulmonary papillary adenocarcinoma.