Atypical periosteal reaction and unusual bone involvement of ameloblastoma: A case report with 8-year follow-up

Unusual radiographic findings of intraosseous ameloblastoma have been reported and discussed. In the case discussed herein, cone-beam computed tomography (CBCT) clearly showed many radiographic features that were ambiguous on conventional radiographs, including an ill-defined periphery, extensive superficial buccal extension with minimal lingual extension, obvious bucco-crestal expansion, and multiple triangular (Codman's triangle-like) areas of periosteal reaction. Based on the above-mentioned findings, the differential diagnosis was a long-term infected benign or low-grade malignant lesion. An incisional biopsy was performed, and the histopathologic diagnosis was acanthomatous ameloblastoma. Recurrence of the lesion was clearly detected on CBCT images at 4 and 8 years after surgery. These unusual radiographic findings have never been reported to be associated with ameloblastoma, and thus may contribute to novel concepts in radiographic interpretation in the future. This report also underscores the important role played by CBCT as a comprehensive diagnostic tool and for definite confirmation of recurrence.