Widespread epithelioid angiosarcoma with ventricular wall involvement in a dog

This paper reports on a canine angiosarcoma, presenting as an "undifferentiated metastasizing tumor". A 14-year-old female Cocker Spaniel was referred to the University of Extremadura Veterinary Clinic for clinical examination after suffering rapid deterioration, with chronic cough, anorexia and cachexia. One week after clinical examination, the dog died of right congestive heart failure and ventricular arrhythmia. Blood counts revealed lymphopenia and platelet depletion. The biochemistry profile was within normal limits, except for a drop in blood urea nitrogen. Cytological evaluation of liver and spleen biopsies revealed clustered anaplastic cells that lacked convincing tissue differentiation. Major findings at necropsy were enlarged spleen and multiple, beige to dark-red nodules ranging from 0.5 to 3 cm in diameter in the heart, lung, liver and spleen. At histological examination, multiple nests of anaplastic epithelioid cells were found in sections from all affected organs. Immunohistochemistry revealed widespread expression of CD31 and Factor VIII-related antigen. The neoplastic cells were negative for CD 18. The diagnosis of epithelioid angiosarcoma, localized in the myocardium, lung, liver and spleen was made. The primary site of the neoplasm could not be determined.