Clinical and histopathological studies of unicystic ameloblastoma diagnosed as odontogenic cyst

Abstract

It is sometimes difficult to differentiate ameloblastoma from odontogenic cysts, especially from dentigerous cysts. In our department, we have experienced four cases of unicystic ameloblastomas which was first diagnosed as odontogenic cyst at the time of initial biopsy.
Patients ages at first visit ranged from 14 to 40 years old. There was a predilection to occur at the molar-ramus region or premolar region of the left mandible and two cases were associated with impacted third molar.
Histological findings of four cases at initial biopsy were thin and flat epithelium which had characteristics of squamous cells that ordinarily line odontogenic cyst. Two showed cytoplastic vacuolization and palisading of basal cells which might be a part of the manifestation of the ameloblastoma. Correct diagnosis of ameloblastoma was done during marsupialization in one case, at enucleation in two cases and recurrence after 16 years in one case.
Causal relation between ameloblastoma and odontogenic cyst was unable to be determined.