Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumor. It can arise de novo, however one-third of cases may arise from a recurrent ameloblastic fibroma, in which case they appear to present at an older age.

A 16-year-old female presented with one month history of right mandibular mass. Computerized tomography (CT) scan showed a large destructive mass. A biopsy of the mass was performed. Histologically, it consisted of a mixed epithelial-mesenchymal odontogenic neoplasm composed of benign islands of well-differentiated ameloblastic epithelium within a malignant fibrous stroma consisting of spindle cells or fibroblasts with a brisk mitotic activity. The malignant spindle cell proliferation showed positive staining with p-53 and a high proliferation index with ki-67. A diagnosis of AFS was rendered.

The differential diagnosis includes other odontogenic sarcomas, ameloblastic carcinosarcoma and spindle cell carcinoma. Treatment of choice is wide surgical excision, with long-term follow-up. Postoperative chemotherapy and radiotherapy has been used successfully in a few reported cases. AFS is a locally aggressive malignant tumor, with regional and distant metastases being uncommon.