Dentinogenic ghost cell tumor (DGCT) is a rare neoplasm, representing 1.9% to 2.1% of all odontogenic tumors. Peripheral DGCT is a rare tumor with only 25 cases previously described in the English literature. The majority of cases have been reported to occur in the anterior part of the jaws. A rare case of peripheral DGCT is reported, located in the lingual side of the anterior mandible of a 68-year-old man. The patient presented a pedunculated painless growth of 1.5cm in diameter. Radiographically, no bone involvement was found. The lesion was excised and histologically characterized by islands of epithelial cells showing ameloblastoma-like features within fibrous background tissue. Dysplasic dentin and ghost cells with calcifications were frequently observed. Areas showing a connection between tumor cells and the overlying mucosa were also identified.

Odontogenic ghost cell tumor (OGCT) is considered as a neoplastic counterpart of the calcifying odontogenic cyst (COC). β-catenin mutations have been described in COC suggesting a critical role in its histogenesis. In this study, we report a patient with OGCT contains a missense mutation on codon 3 (ACT -> TCT). Immunohistochemistry showed nuclear, cytoplasmic, and membranous accumulation of β-catenin in the tumor cells. TUNEL assay showed positive signals in nucleated cells adjacent to the ghost cells. Our data suggest that β-catenin plays an important role in the tumorigenesis of OGCT. OGCT may developed by improper differentiation process coordinated by WNT signaling pathway. Further studies are needed to determine a genotypic/phenotypic characteristics of ghost cell containing odontogenic lesions.

A case of odontogenic ghost cell tumor (OGCT) with clear cell components occurred in the mandible of a 63-yearold man. The tumor revealed ameloblastomatous type epithelial components together with clusters of ghost cells and dentinoid juxtaposed to the odontogenic epithelium. In addition, some areas of the tumor tissue showed sheets and islands of clear, glycogen-rich epithelial cells, separated by a thin fibrous connective tissue stroma. Both ameloblastic and clear cells showed positive immunoreactivities for cytokeratin 19 and AE1/3. It is not known whether this tumor represents a clear cell differentiation of a preexisting OGCT or a separate and distinct neoplasm derived de novo from odontogenic epithelium. This tumor was preferred the term clear cell odontogenic ghost cell tumor, which captures the clear cell components, one of the tumors most prominent distinguishing features