A case of thyroglossal duct cyst in the oral floor

Thyroglossal duct cyst is a congenital anomaly resulting from retention of a thyroglossal duct during embryonic development. It usually occurs in the midline of the neck and rarely arises in the oral floor.We describe a case of thyroglossal duct cyst occurring in the oral floor of a 51-year-old woman.The chief complaint was an elastic soft mass in the oral floor. We initially diagnosed a cystic lesion in the oral floor on the basis of computed tomographic findings. We enucleated the mass vi a atransoral approach. We did not resected the hyoid bone.Histopathologically, the cyst wall was covered with columnar and stratified squamous epithelium. A thyroid like tissue was found in the connective tissue.We found only 27 cases of thyroglossal duct cyst in the oral floor, including our case, reported in Japan.The postoperative course was uneventful, with no evidence of recurrence for 2 years 6 months after the operation.