Clinical and pathological features of desmoplastic ameloblastoma: a literature review with three case reports

Desmoplastic ameloblastoma is a rare variant of benign odontogenic tumors. Our objective was to describe the clinical and pathological features of desmoplastic ameloblastoma. Three cases of desmoplastic ameloblastoma that were treated in the authors' department were reviewed and analyzed along with radiological and histological data. The findings obtained from pathological examinations of two solid ameloblastomas served as controls. Moreover, 91 desmoplastic ameloblastoma cases in the literature were reviewed. Desmoplastic ameloblastoma is most commonly observed in the anterior and premolar regions of the mandible and maxilla, with a radiolucent and radiopaque appearance. After surgical resection, no recurrence was observed. On pathological examination, desmoplastic ameloblastoma was present in irregular and compressed epithelial islands scattered among massive stroma. In the epithelium, desmoplastic ameloblastoma expressed CK19 weakly to strongly and TGF-beta(1) moderately to strongly, while vimentin was expressed strongly in the stroma. However, solid ameloblastoma tumors had strong CK19 expression, weak to strong TGF-beta(1) expression, and negative to weak vimentin expression. The review of the literature was in agreement with our cases. Desmoplastic ameloblastoma has distinctive clinical and pathological features compared with solid ameloblastoma, and it might originate from an earlier odontogenic epithelium precursor or transition from ectomesenchyme.