Body condition score (BCS) 5-6/9. The skeletal structures are physiological. The caudo-ventral liver lobe is rounded and extends just beyond the costal arch. A moderate amount of air is present in the stomach. The gastric axis is parallel to the ribs. A soft tissue structure with a triangular cranial outline is evident ventro-caudal to the stomach; its caudal component is not included in the view (tail of spleen). As far as included in the images, the retroperitoneal and peritoneal detail is good.

The thoracic volume is physiological and the contour of the diaphragm is relatively straight.

The left hemithorax is filled with a soft tissue opaque mass extending from rib 6 to the diaphragm. The contour of the mass is slightly rounded on the cranial, ventral and medial aspects. Silhouette signs exists between mass, heart and left diaphragm. Carina and cardiac shadow have been displaced ventrally and to the right by the mass; the left main stem bronchus is also displaced ventrally. The lobar bronchus for the diaphragmatic lobe (right caudal lobe) can only be appreciated just caudal to the carina.

The cardiac silhouette shows no obvious changes. The pulmonary vessels also appear physiological.

• Space occupying lesion left caudal thorax
• Aerophagia
• Slightly rounded caudo-ventral liver lobe

The most likely cause for the mass is a tumour in the left caudal lobe. Differential diagnoses include granuloma and abscess.

A diaphragmatic rupture can be ruled out due to a physiological position of the stomach. An extra-pleural mass is also unlikely due to the described radiographic appearance.

The aerophagia is most likely stress related however, small intestinal loops are not included in the views thus chronicity cannot be ruled out entirely. Aerophagia due to dyspnea is a differential diagnosis.

The rounded appearance of the ventral liver lobe is most likely due to the projection of the gall bladder over the hepatic contour which is a physiological occurrence in the feline species. The prominence can be the result of prolonged inappetence but outflow obstruction is a differential diagnosis.

Histo-pathology revealed a carcinomatous process in the lung; most likely a broncho-alveolar carcinoma. Adenocarcinoma is a differential diagnosis.