Palatal Osseous Choristoma.

Osseous choristoma of soft tissue in the oral cavity is rare. The choristoma is a tumor-like mass of normal cells in an abnormal location. In this report, a case of osseous choristoma of the palate in a 37-year-old male patient was reported. Approximately 6 × 5 mm pedunculated healthy colored and hard mass was observed in the median palate. The mass was surgically removed. Microscopic examination of the hematoxylin and eosin-stained sections of the mass revealed that a dense lamellar bone nodule was surrounded by fibrous connective tissue under the squamous epithelium. Immunohistochemical analysis revealed that the mass was negative for S-100 protein, cytokeratin, and epithelial membrane antigens. According to these findings, the final pathologic diagnosis confirmed that the mass was an osseous choristoma.