舌根部に発生した骨性分離腫の3例

Three cases of osseous choristoma occurring at the base of the tongue

はじめに

　舌根部に生じる骨性病変の報告は比較的稀である。病変の好発部位が舌盲孔付近であることから，発生学上胎生期鰓弓軟骨の遺残，迷入，または化生による分離腫として報告される場合が多い。今回われわれは，舌根部に生じた骨性分離腫の3例を経験したので，若干の文献的考察を加えて報告する。

　Lingual osseous choristoma is rare. We reported three cases of osseous choristoma occurring at the base of the tongue. Computed tomography（CT）showed a radiopaque round shadow at the base of the tongue, while magnetic resonance imaging（MRI）showed no evidence of lesions. We resected the tumor under local anesthesia in one case and under general anesthesia in 2 cases. In case 1, MRI showed the existence of thyroglossal cyst. We concluded that osseous choristoma occurring at the base of the tongue could be a rare entity resulting from developmental defects at early stages of foramen caecum and thyroid gland embryogenesis.