The cardiovascular structures are normal in size and shape. There is a soft tissue opacity mass in the dorsal thorax, localized to the left caudal subsegment of the left cranial lung lobe on the dorsoventral and ventrodorsal projections, very close to the hilus. The remainder of the pulmonary parenchyma is normal. No abnormalities are seen in the cranial mediastinum or pleural space. Osteophytes are present on the caudal humeral heads.
Papillary adenocarcinoma of the left cranial lung lobe with bronchial invasion. The bronchial invasion was identified on the CT images as soft tissue attenuating material within the bronchial lumen. This was confirmed after lobectomy and histopathology.