What is your diagnosis? Intestinal mass in a cat.

Roche), ×100 objective gl DISCUSSION Intestinal osteosarcoma is an extremely rare neoplasm of domestic animals, with three cases currently reported in cats.1,2 Histologically, the diagnosis of osteosarcoma is supported by the presence of malignant mesenchymal cells associated with the production of osteoid and/or tumorous bone tissue. The histopathologic morphology of osteosarcoma can vary because of the pleomorphism of malignant osteoblasts (spindle-shaped, ovoid, or rounded cells) and the variable amount and appearance of osteoid.3 Cytologic preparations from osteosarcomas are usually moderately to highly cellular. Lymph node cytology revealed marked lymphoid hyperplasia with a neoplastic cell infiltration with the same neoplastic cells seen in the intestinal masses. [Extracted from the article]