Diffuse bronchiolo‐alveolar carcinoma in a dog

An eight‐year‐old female German wirehaired pointer was presented with signs of respiratory distress. Clinical examination, laboratory results, thoracic radiography and echocardiography indicated the presence of a diffuse interstitial lung disease with secondary appropriate erythrocytosis, pulmonary hypertension and cor pulmonale. Transthoracic fine needle aspiration biopsy of the lung suggested malignant epithelial neoplasia. A primary lung cancer with an unusually diffuse distribution of miliary/micronodular lesions was found at postmortem examination. Histological diagnosis was bronchiolo‐alveolar carcinoma. Bronchiolo‐alveolar carcinoma can occasionally occur in a diffuse fashion involving most or all of the lung parenchyma. In man, diffuse bronchiolo‐alveolar carcinoma is considered a great imitator of other, more common diffuse interstitial forms of lung disease. This case report indicates that it is also a differential diagnosis to consider in dogs.