Today’s case is a 15-year-old Yorkshire Terrier with cough causing weakness and collapse. How would you describe the lesion?
There is an alveolar pattern in the cranial subsegment of the left cranial lung lone with visible air bronchograms and a lobar sign. Patchy, ill-defined nodules are present in the caudal subsegment of the left cranial lung lobe, coalescing to an alveolar pattern ventrally. There is a thin-walled bulla in the dorsal and medial portion of the left caudal lung lobe. The remainder of the pulmonary parenchyma is normal. No abnormalities are noted in the cardiovascular structures, mediastinum, or pleural space. In the portion of the abdomen included, the stomach is moderately distended with gas.
The left cranial lung lobe is most likely affected by primary pulmonary neoplasia. Infectious inflammatory disease is less likely.
Papillary adenocarcinoma affecting the left cranial lung lobe.