Clear cell adenomatoid odontogenic tumour and dentigerous cyst: an uncommon hybrid combination - case and review

Odontogenic tumours and cysts have a characteristic presentation, histopathologically and clinically. The diagnostic criteria and nomenclature are distinct as elaborated in 2017 WHO classification. But one can occasionally and infrequently find an association between different odontogenic tumours and cysts, like calcifying epithelial odontogenic tumour (CEOT) and adenomatoid odontogenic tumour (AOT), CEOT and ghost cell tumour. Some of the odontogenic tumours and cysts share the site of occurrence, intraosseous location, teeth involved/quadrant involved and histopathology too. Hence these lesions are considered for differential diagnoses in most cases. But some instances report hybrid or associated tumours and cyst cases. Here we present a case of dentigerous cyst in association with AOT that showed variation in cell type, pattern and induction pattern.