Adenoid ameloblastomas: expanding the clinicopathological spectrum with five new cases

To describe the clinicopathological and immunohistochemical characteristics of adenoid ameloblastoma (AdAM), a rare odontogenic neoplasm recognised as a distinct entity in the 2022 WHO classification, and to highlight the diagnostic challenges associated with its overlapping features.

A retrospective analysis was performed on five cases of AdAM diagnosed between 2021 and 2023 at a tertiary care institution. Clinical presentation, radiographic findings, histopathological features, and immunohistochemical profiles were reviewed and systematically analysed.

All patients presented with painless jaw swelling, with a mean age of 40.8 years and a female-to-male ratio of 4:1. Three lesions involved the posterior mandible and two involved the maxilla. Radiographically, four tumours were radiolucent, whereas one exhibited mixed radiolucent-radiopaque features. Histologically, all cases demonstrated characteristic pseudoductal and cribriform patterns with whorled epithelial formations. Additional findings included clear cells, dentinoid deposition, spindle cell areas, ghost cells, and keratin pearl formation. Immunohistochemically, al tumours were positive for AE1/AE3, CK5/6, CK14, and CK19 and negative for CK7. The Ki-67 proliferation index ranged from 2% to 30%, with low-level p53 expression in all cases. One tumour showed BRAF V600E positivity.

AdAM represents a distinct but diagnostically challenging odontogenic tumour with locally aggressive behaviour and potential for recurrence. Recognition of its characteristic histopathological patterns, supported by immunohistochemical findings, is critical for accurate diagnosis and appropriate therapeutic management.