Ultrasonographic and histopathological features of concurrent jejunal and skeletal muscle metastases in a cat with suspected pulmonary carcinoma

Abstract A 14‐year‐old neutered female domestic shorthair cat was referred for investigation of acute vomiting, inappetence, lethargy, and suspected laboured breathing. Ultrasonography revealed multifocal, uneven thickening of the jejunal muscular layer, with preserved layering. One muscular mural lesion displayed two small, ill‐defined hyperechoic foci and adjacent mesojejunal hyperechogenicity and thickening. An intramuscular mass was identified caudal to the left stifle. Thoracic imaging (radiography and CT) demonstrated a cavitated pulmonary mass in the left caudal lung lobe. Histopathological examination of biopsies confirmed intestinal and skeletal muscle metastases of a poorly differentiated carcinoma, with the pulmonary lesion suspected to represent the primary tumour.