Granular cell odontogenic tumor is a rare lesion consisting of densely packed granular cells with numerous scattered strands of odontogenic epithelium interspersed throughout the tissue. A case of this tumor arising in the mandible of a 51-year-old man is reported. Radiological examination revealed a welldefined unilocular radiolucency in the left side of the mandibular body. Marginal resection of the mandible was performed under general anesthesia. Histopathologically, the tumor was composed of large, round cells with abundant cytoplasm containing eosinophic granules and nests of odontogenic epithelium. On the basis of these clinical and histopathological findings, we made a diagnosis of granular cell odontogenic tumor of the mandible. We also discuss the pathogenesis of these granular cells.
