Case ReportEquine Mandibular Fibrosarcoma in Two Horses: Clinical, Diagnostic, and Therapeutic Considerations

- Two cases presented for weight loss and a large mandibular swellings: one involving the caudal aspect of the left horizontal mandible and the other presented for a soft tissue swelling on the labial mucosa adjacent to 304.
- Histopathology of both masses diagnosed fibrosarcomas.
- Case 2 underwent a left subtotal rostral hemimandibulectomy that proved to be successful in complete resection of the fibrosarcoma with a comfortable and cosmetic postoperative outcome.
- Computed tomography assessment of tumor penetration into deeper tissues can be achieved, thus facilitating complete surgical excision.
- Postoperative complications are few, and the cosmetic and clinical outcome is favorable.

A 25 year old Arabian gelding (case 1) presented for a large mandibular swelling involving the caudal aspect of the left horizontal mandible and a 14 year old Quarter Horse gelding (case 2) presented for a soft tissue swelling on the labial mucosa adjacent to 304. Both horses were bright and alert on presentation. Computed tomography allowed for further characterization regarding the extent of bone penetration within the lesions. This facilitated surgical planning and resection in Case 2. Histopathology of both masses diagnosed fibrosarcomas. Case 1 was humanely euthanized due to the severity of bone involvement and the grave prognosis. Case 2 underwent a left subtotal rostral hemimandibulectomy that proved to be successful in complete resection of the fibrosarcoma with a comfortable and cosmetic post-operative outcome. Surgeries that were once deemed radical should be considered for the treatment of neoplastic masses involving the soft tissues and bony structures of the oral cavity. With the aid of computed tomography, assessment of tumor penetration into deeper tissues can be achieved, thus facilitating complete surgical excision.