Low-Grade Ameloblastic Fibrosarcoma of the Mandible: A Case Report with Initial Misdiagnosis

Background: Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumor characterized by benign epithelial components and a malignant mesenchymal stroma. Accurate diagnosis is challenging, especially when initial biopsy samples are limited. Case Presentation: A 35-year-old male presented with a progressively enlarging swelling on the left side of his face. Clinical examination revealed a firm, non-tender mass in the left mandibular region, resulting in mild facial asymmetry. Intraoral evaluation showed buccal cortical expansion in the posterior mandible, accompanied by slight mobility of the adjacent teeth. Panoramic radiograph and cone beam computed tomography (CBCT) revealed an ill-defined, multilocular radiolucent lesion involving the left mandibular body and ramus, with cortical bone perforation and mild soft tissue extension. An incisional biopsy initially diagnosed ameloblastic fibroma (AF). The patient underwent segmental mandibulectomy, and final histopathological evaluation revealed low-grade ameloblastic fibrosarcoma. Reconstruction was performed using a reconstruction plate and autogenous iliac bone graft. The postoperative course was uneventful, with no recurrence observed during a 6-month follow-up. Conclusions: This case underscores the diagnostic challenges of AFS and highlights the importance of comprehensive histopathological evaluation. Early detection, accurate diagnosis, and complete surgical excision with clear margins are critical for best outcomes.