Ameloblastic fibroma: A stage in the development of a hamartomatous odontoma or a true neoplasm? Critical analysis of 162 previously reported cases plus 10 new cases

Objective To analyze neoplastic and hamartomatous variants of ameloblastic fibromas (AFs). Study Design Analysis of 172 cases (162 previously reported, 10 new). Results AF emerged as a lesion primarily of children and adolescents (mean age, 14.9 years), with about 80% diagnosed when odontogenesis is completed (age, < 22 years). Around 28% of all AFs were small and asymptomatic, and 72% exhibited moderate-to-severe bone expansion. Conclusions There are 2 variants of AF: neoplastic and hamartomatous. Lesions in patients aged >22 years are considered true neoplasms, while those in younger patients may be either true neoplasms or odontomas in early stages of development. Although the histopathology of hamartomatous and neoplastic variants of AF are indistinguishable, clinical and radiologic features can be of some help to distinguish between them. Asymptomatic small unilocular lesions with no or minimal bone expansion in young individuals are likely to be developing odontomas, and large, expansile lesions with extensive bone destruction are neoplasms.