A report of a perivascular wall tumor in an axillary region of a pit bull

Background: Perivascular Wall Tumors (PWTs) are a heterogeneous group of mesenchymal tumors which originate from various cells of the vascular wall. Clinically, PWTs are presented as firm, palpable subcutaneous or cutaneous masses and are most commonly seen on the limbs, trunk, or around joints. Pulmonary metastasis is considered uncommon. Recurrence rates are relatively low when complete surgical margins are achieved. Methods: A ۱۲-year-old female Pit Bull was presented with a firm-solid mass in the subcutaneous in the left axillary region, at the caudal distal part of the left humerus which had been present for approximately six months. Radiography revealed a soft tissue mass in the same area, while ultrasonography demonstrated a well-encapsulated, heterogeneous mass (۳.۴۵ × ۱.۵۱ cm) with visible vascular supply. CBC and biochemical evaluation were measured and all were within normal range. During Surgical excision, following an incision over the swelling, a well-encapsulated mass was clear. The surrounding tissues were dissected bluntly and sharply, and the tumor was removed without the need for vascular ligation. For surgical site closure, the subcutaneous tissue was sutured with ۳-۰ PDS and skin was closed with ۳-۰ nylon. A pressure bandage was applied to prevent dead space formation. Histopathological examination showed perivascular whorls of spindle-shaped cells with interlacing bundles and abundant extracellular matrix, accompanied by stellate cells with low mitotic activity and minimal pleomorphism. The final diagnosis was reported as a Perivascular Wall Tumor (PWT). Results: Soft tissue sarcomas make up approximately ۱۵% of all cutaneous and subcutaneous tumors in dogs. Among them, PWTs are shown to be the most common subtype, and according to previous studies, about ۷۹.۶% of cutaneous STSs were classified as PWTs. Major prognostic factors for canine PWTs include completeness of surgical margins, histologic grade, tumor depth, and overall size. Conclusion: Complete excision with clean margins is crucial to prevent recurrence in canine perivascular wall tumors. Accurate histopathologic diagnosis ensures better prognosis.

کلیدواژه ها:

perivascular wall tumor ، sarcoma ، axillary ، surgical excision ، histopathology ، pit bull