Combined Adenomatoid Odontogenic Tumor and Calcifying Epithelial Odontogenic Tumor: A report of three cases and a review of the literature

Abstract

Odontogenic tumors present considerable histopathologic diversity. Lesions with combined features of more than one entity present a diagnostic challenge. One such lesion described in the literature is the combined lesion of adenomatoid odontogenic tumor (AOT) and calcifying epithelial odontogenic tumor (CEOT). Due to its rarity, there is limited data regarding its histopathologic features and clinical behaviors. Here, we present three cases of odontogenic tumors with features of both AOT and CEOT. AOT usually occurs in female teenagers with predilection for the anterior maxilla and is often associated with an impacted tooth. In contrast, CEOT is often found in patients at the age of 30-50 years and has a predilection for the posterior mandible. CEOT is also often associated with impacted teeth. We searched the cases of Oral Pathology Lab at NYPQ from 1986-2021 and identified 63 AOTs, 24 CEOTs, and 3 AOT/CEOTs. All 3 AOT/CEOT cases were from females between ages 13-19 and were described as cystic lesions associated with impacted teeth in the anterior maxilla. Radiographic findings were described as mixed or radiolucent. The demographics and sites of our AOT/CEOT cases resemble those of AOT as opposed to CEOT. The histology revealed odontogenic epithelial tumors composed of polygonal and spindle-shaped cells arranged in whorls, rosettes, and gland-like structures. Admixed throughout the tumors were sheets and strands of polyhedral epithelial cells with variably shaped nuclei set in abundant eosinophilic cytoplasm. Amorphous eosinophilic material and concentric calcifications were noted throughout. A Congo Red stain was positive in the one case it was performed. While both collision and hybrid theories have been suggested etiologies for AOT/CEOT, the admixture of the two components supports the latter. The similarity of our cases to the demographics of AOT, and the difference in sites and demographics of AOT and CEOT speaks against the collision theory.