Primary pulmonary artery osteosarcoma in a dog

Abstract

An eight-year-old neutered female Golden Retriever presented for evaluation of lethargy, coughing, haemoptysis and pyrexia. Thoracic radiography identified a diffuse nodular pattern affecting all lung lobes and echocardiography revealed a hyperechoic intraluminal mass within the pulmonary artery. Postmortem examination confirmed the presence of a small irregular raised non-occluding sessile intraluminal mass infiltrating the wall of the pulmonary artery. It was composed of plump spindle shaped or polygonal cells interspersed between and occasionally lining variably sized trabeculae of osteoid consistent with a diagnosis of osteoblastic osteosarcoma. Secondary pulmonary masses of similar size to the primary neoplasm and large tumour emboli within pulmonary vessels suggested early metastasis. Primary osteosarcoma of the pulmonary artery has not been reported in the dog and its clinical presentation, gross and microscopic features, biological behaviour and tissue of origin are discussed.