Microcystic Calcifying Epithelial Odontogenic Tumor

Abstract

Microcystic variant of calcifying epithelial odontogenic tumor is rare. We herein describe an additional well-documented case of microcystic CEOT. The affected patient is a Guatemalan 42-year-old female with an expansile well-defined mixed radiolucent-radiopaque lesion located in the right posterior mandible. The lesion was associated to an unerupted third molar. Histopathologic examination revealed nests and cords of moderately pleomorphic, eosinophilic polyhedral epithelial cells surrounded by a fibromyxoid stroma. The neoplastic cells showed microcystic pattern made of pseudo-glandular spaces with variable diameter. Occasional amyloid deposits and calcified acellular material were observed. Tumor cells were positive for AE1/AE3, CK14, CK19, p63, CD138, and beta-catenin. Conservative surgical resection was performed with an uneventful immediate post-surgical follow-up. After 1 year follow-up there is no evidence of recurrence. Pathologists should be aware of this unusual microcystic presentation of CEOT, which may pose a diagnostic challenge and potential diagnostic dilemma.

Keywords: Calcifying epithelial odontogenic tumor; Immunohistochemistry; Mandible; Microcystic.

Fig. 1

An expansive and well-defined mixed radiolucent–radiopaque lesion located in the ascending ramus of the mandible, in relation to an unerupted third molar. Cortical bone expansion and thinning of the inferior cortical bone is evident

Fig. 2

a, b Microcystic compartments of varying size resembling pseudo-glandular structures in a fibromyxoid stroma. c Extracellular amyloid deposits within a pseudo-ductal structure were d intermingled with typical cords of polyhedral eosinophilic epithelial cells and close to calcified material. e, f Congo red positive for amyloid material, which showed green birefringence under polarized light (HE, a ×25, b–f ×200)

Fig. 3

Tumor cells were positive for a AE1/AE3, b CK14, c CK19, d p63, e CD138, and f beta-catenin (IHC, ×200)