Case Report: Surgical management of mandibular oral histiocytic sarcoma in a ragdoll cat with favorable outcome.

Feline oral histiocytic sarcoma (HS) is an exceptionally rare malignancy with limited clinical characterization and a poor prognosis. This report describes a case of mandibular HS in a 6-year-old Ragdoll cat that achieved a favorable local control following surgical management alone. The cat presented with left mandibular swelling, and diagnostic imaging revealed a poorly demarcated mass with extensive osteolysis of the mandible. Histopathological and immunohistochemical findings supported the diagnosis of a poorly differentiated malignant mesenchymal neoplasm with histiocytic differentiation. Rostral mandibulectomy with 0.5 cm surgical margins was performed. Postoperative recovery was uneventful, and no adjuvant chemotherapy was administered owing to financial constraints. The patient presented with clinical signs of lethargy and anorexia 7 months after surgery. On thoracic radiography, several soft tissue opacity masses throughout the bilateral lung lobes were identified. On ultrasonographic examination, multiple masses were also identified in the liver and kidneys, raising suspicion for metastatic lesion. However, there was no evidence of recurrence at the primary surgical site. The patient was euthanized. Compared with previously reported cases that showed poor outcomes despite additional therapies, this case suggests that surgical resection may provide successful local control in select cases. This report expands the clinical spectrum of feline oral HS and highlights the potential role of surgical excision as a primary treatment.