GIANT-CELL VARIANT OF MALIGNANT FIBROUS HISTIOCYTOMA IN DOGS - 10 CASES (1986-1993)

Signalment, tumor sites, clinicopathologic, radiographic, and ultrason ographic features, as well as treatment protocols and survival informa tion, were evaluated for to dogs with a histologic diagnosis of giant cell variant of malignant fibrous histiocytoma. Common clinical findin gs included subcutaneous masses, weight loss, anorexia, and lethargy. Laboratory abnormalities included anemia, hypoalbuminemia, and high co ncentrations of serum hepatic enzymes. Radiography and ultrasonography were useful in staging the extent of metastasis. seven dogs had tumor metastasis at the time of diagnosis. Two other dogs developed evidenc e of metastasis during the course of treatment. The most common sites of tumor involvement were subcutaneous tissues, lymph nodes, liver, an d lungs. Treatment protocols included surgical resection, intraoperati ve radiotherapy, and chemotherapy. Median survival time of all dogs wa s 61 days. Median survival time of the 6 treated dogs was 161 days. Fi ndings on necropsy revealed metastasis with multiple organ involvement . The giant cell variant of malignant fibrous histiocytoma was determi ned to be a highly metastatic neoplasm in dogs, which may be responsiv e to surgical excision, chemotherapy, or radiotherapy.