Large Segmental Mandibulectomy for Treatment of an Undifferentiated Sarcoma in a Horse

OBJECTIVE: To describe a large segmental (sub-total) mandibulectomy for removal of an undifferentiated sarcoma in a horse. STUDY DESIGN: Clinical report. ANIMALS: A 10-year-old mare. METHODS: A combination of methods including computed tomography (CT) were used to diagnose a large undifferentiated sarcoma of the right mandible. A large segmental mandibulectomy extending from 3 cm below the right temporomandibular joint to immediately caudal to tooth 407 was used to perform an en-bloc resection of the mass under general anesthesia. RESULTS: Surgery time was 11 hours and 35 minutes and total anesthesia time, 12 hours and 40 minutes. The mare was eating well 3 days after surgery. Some postoperative skin sloughing occurred, but the cosmetic and functional outcome was good. The mare continued to do well, with no evidence of disease recurrence, 24 months after surgery. CONCLUSIONS: Three-dimensional reconstruction of the CT images was instrumental in surgical planning. A very large portion of the mandible can be removed in a horse with acceptable cosmetic and functional outcome.