Ameloblastic fibrosarcoma arising de novo in the maxilla.

An ameloblastic fibrosarcoma (AFS) arising in the maxilla of a 14-year-old male is described. The tumor originated from the alveolar bone of the right maxilla with no apparent history of pre-existing lesion. Histologically, the lesion was composed of benign-appearing epithelial islands and strands scattered within an exceedingly cellular mass of mesenchymal tissue comprising a large number of stellate-and spindle-shaped fibroblast-like cells with marked pleomorphism. Occasional cementum-like calcification was also noted. Immunohistochemically, the neoplastic mesenchymal cells were positive only for vimentin, whereas the ameloblast-like epithelial component showed a distinctly positive reaction for wide-spectrum keratin and squamous cytokeratin. Clinicopathological features of the current case, as well as previously reported examples of AFS originating from the maxilla, are briefly discussed.