Rare case of hemangiopericytoma in a domestic short-haired cat

A two-year-old queen was referred to the surgery section of veterinary hospital with lateral recumbency position and the primary diagnosis of dystocia. The queen was highly lethargic and dehydrated, with a pale mucous membrane, a rectal temperature of 37.3 °C, and no vaginal discharge during first inspection. The primary examination revealed a big mass in the abdominal cavity, which was followed by other diagnostic investigations. Due to a huge and encroaching tumor and the patient's owner's refusal to accept any further therapies, the queen was euthanized during an exploratory celiotomy. This report describes a large Hemangiopericytoma (HPCy) in a domestic short-haired queen diagnosed based on physical examination, radiography, ultrasonography, histomorphology, and immunohistochemical reactivity. The results of pathology revealed a whorls around blood vessels and the "fingerprint" pattern of tumor with negative S-100 immunohistochemistry staining.   In dogs, HPCy is a common neoplasm, but it is a seldom finding in cats. There is no previous report of HPCy in the abdominal cavity as observed in the presented case to the authors' knowledge.