Primary Pulmonary Adenocarcinoma in Cats – Case Report

Abstract

Primary pulmonary adenocarcinoma is a rare neoplasm in cats, predominantly affecting geriatric animals. This report describes a 17-year-old spayed female domestic cat with nonspecific clinical signs (progressive anorexia, weight loss, intermittent vomiting, lethargy) and mild dyspnea. Passive exposure to household cigarette smoke was noted as a potential risk factor. Physical examination revealed severe dehydration and pale mucous membranes. Laboratory evaluation showed neutrophilic leukocytosis and thrombocytopenia; serum biochemistry was unremarkable, and serology was negative for FeLV and FIV. Thoracic radiographs demonstrated multiple diffuse pulmonary opacities consistent with metastatic pulmonary disease. The patient deteriorated and died four days after initial presentation, illustrating the rapid progression of this condition. Necropsy revealed a sanguineous pleural effusion, a caseous pulmonary mass (5,6 x 5,0 cm in the left caudal lobe) and multiple secondary nodules throughout the lung parenchyma. Histopathology confirmed a grade II bronchioloalveolar adenocarcinoma with invasive, pleomorphic malignant cells, papillary proliferation and areas of necrosis. This case underscores the aggressive nature and poor prognosis of feline pulmonary adenocarcinoma, highlighting the need to include it in the differential diagnosis of respiratory disease in older cats.