Background: Unicystic ameloblastoma (UA) is a distinct variant of ameloblastoma displaying a large cystic cavity lining by ameloblastomatous epithelium and can present a wide variety of histologic patterns.
Case report: We herein reported an unusual UA occurring in the mandible of a 23-year-old male patient who exhibited luminal, intraluminal and mural patterns, as well as acanthomatous, basal cells and granular cell variants. In addition, hyaline ring granulomas, an extraordinary finding in ameloblastoma, were found. The nature of several microscopic variants in this tumor and the possible significance of their presence have also been discussed.
Conclusions: We believe this to be the first case reported in which a UA displayed multiplicity of histopathological patterns in a single lesion.
Keywords: Ameloblastoma; histopathology; odontogenic tumours.