Concurrent right atrial myxoma with visceral haemangiosarcoma in a dog

Abstract

A 10‐year‐old crossbreed (labradoodle) was presented with an acute history of vomiting and diarrhoea, with supraventricular tachycardia and ventricular premature complexes. Physical examination revealed mild tachycardia, but no significant abnormalities otherwise. Investigations with echocardiogram and computed tomography identified a right atrial mass, nodular interstitial lung pattern, multiple nodules throughout the hepatic parenchyma and peritoneal effusion. Abdominocentesis confirmed a haemoabdomen. Treatment was declined and the dog was euthanased the same day. Histopathology of the cardiac mass confirmed a cardiac myxoma, which stained Alcian blue‐positive, demonstrating the mucin content of the tumour. The hepatic lesions were factor VIII‐positive, consistent with a visceral haemangiosarcoma.