Hemangiosarcoma in cats: 53 cases (1992-2002).

Objective—To characterize the biological behavior and prognostic factors associated with hemangiosarcoma in cats. Design—Retrospective case series. Animals—53 cats with hemangiosarcoma. Procedures—Data were retrieved from a state veterinary diagnostic laboratory, 3 veterinary colleges, and a private practice. Results—Cutaneous and subcutaneous tumor locations were more common than visceral (abdominal and thoracic) and oral locations. Surgical excision was the primary treatment in 47 cats. Tumor-free surgical margins were more likely in cutaneous than subcutaneous lesions and were associated with longer survival times. Local recurrence was observed in 6 of 12 cats with subcutaneous lesions for which follow-up was available. Metastatic disease was detected in 5 of 13 cats with adequate staging at initial diagnosis. A sixth cat had pulmonary metastases at the time of euthanasia. In 4 of 10 cats with visceral hemangiosarcoma, the diagnosis was made at necropsy or they were euthanized at the time of diagnosis....