Clear cell cystic variant of calcifying epithelial odontogenic tumor

Abstract

Calcifying epithelial odontogenic tumor (CEOT) is a solid, locally aggressive, benign odontogenic neoplasm characterized by sheets and nests of polyhedral epithelial cells exhibiting eosinophilic and less often clear cytoplasm, occasional nuclear pleomorphism without mitotic activity, calcifications, and deposits of amyloid. A cystic variant has been reported only twice. Herein, we present an additional example of cystic CEOT occurring in a 31-year-old male and featuring clear cell epithelial lining with deposits of amyloid and osteodentin.

Fig. 1

a Orthopantomogram. Unilocular mixed radiopaque/lucent, expansile and locally aggressive lesion, located in the left posterior mandible and ascending ramus; b CT. Osteolytic lesion is seen with expansion of surrounding tissue and a central area isodense to bone

Fig. 2

Gross features. Portion 1 features cystic cavity with projections into the lumen. Portion 2 features calcified spherical and irregular mass

Fig. 3

a Cystic cavity (CC) lined by odontogenic epithelium of generally uniform thickness, with focal necrosis (arrow) (H&E ×40); b Clear cells in the cystic lining revealing intracellular and eosinophilic extracellular material (H&E ×400); c Positive diastase resistant deposits (PAS. diastase stain ×400); d Amorphous, eosinophilic hyalinized material exhibiting apple-green birefringence after polarization (Congo red stain ×100); e Calcified material with characteristics of osteodentin (H&E ×100); f Round eosinophilic globules consistent with “thanatosomes” (arrows) (H&E ×400) and f’ “thanatosome” in detail (asterisk) (H&E ×1,000)