Extraskeletal chondrosarcoma in the abdominal cavity of a cow

A 25-month-old female crossbred cow presented with astasia, emaciation, and stunted growth. Macroscopic examination revealed a large mass in the abdominal cavity, approximately 100 × 30 × 30 cm. Microscopic examination revealed that the mass consisted of multilobular mature and immature cartilaginous matrices with chondrocytic cells, surrounded by spindle to pleomorphic mesenchymal tumor cells. The cartilaginous matrices consisted of hyaline and elastic cartilages, as confirmed with Azan stain, and Victoria Blue and Van Gieson stain. Immunohistochemistry revealed that the chondrocytic and mesenchymal cells both expressed S-100. The tumor was diagnosed as an extraskeletal chondrosarcoma in the abdominal cavity of this cow.

Primary leiomyosarcoma of the jugular vein in a dog

A four-year-old, male, Labrador retriever was referred for removal of a spindle cell sarcoma involving the right jugular vein. A post-contrast CT scan showed a seven-centimeter subcutaneous mass originated from the right external jugular vein, which was partially obstructed and showing contrast stasis, suggested a primary intravascular tumor of the jugular vein. The mass was resected, and histological evaluation was consistent with grade II intravenous spindle cell sarcoma of the jugular vein. Immunohistochemical positivity for vimentin, desmin, and αSMA antibody and negativity for S-100 protein confirmed venous leiomyosarcoma. The dog received five doses of intravenous doxorubicin, and there was no recurrence of the tumor 30 months post treatment. In dogs, primary intravascular sarcomas are rare and primary venous leiomyosarcoma has not been described. A venous tumor may be considered as a differential diagnosis in dogs with ventral neck swelling.

Aortic chondroid neoplasia in two Labrador Retriever dogs

In the same week, two Labrador Retriever dogs presented to The Ohio State University Veterinary Medical Center for cardiac evaluation. The presenting signs in both dogs included: weight loss, weakness, lethargy, and decreased femoral pulses. The first dog presented in cardiogenic shock and biventricular congestive heart failure, which initially responded to treatment; however, the dog was euthanized due to deteriorating clinical condition. In contrast, the second dog had a milder clinical course without signs of congestive heart failure, and remained stable over the 2-month period of clinical evaluation prior to euthanasia. Echocardiographic evaluation revealed a dilated cardiomyopathy phenotype in the first dog, while a space-occupying intraluminal mass originating at the aortic valve with preserved left ventricular systolic function was observed in the second dog. At autopsy, each dog had a large obstructive luminal mass affecting the ascending aorta and arch. Histopathology revealed that the mass in the first dog was consistent with a benign chondroma, while in the second dog the morphologic characteristics, mitotic activity, and infiltrative growth justified a diagnosis of chondrosarcoma. This report presents the contrasting clinical disease progression and findings in two dogs with aortic neoplasia, with a proposed pathogenesis of cardiac failure secondary to aortic neoplasia.