Follicular Thyroid Carcinoma Within a Thyroglossal Duct Cyst in Adult.

Thyroglossal duct cyst carcinoma is a rare malignancy, with an incidence of 0.7% to 1.6%. Most cases of thyroglossal duct cyst carcinoma are papillary carcinoma, with follicular carcinoma having been rarely reported. In this study, a 33-year-old man presented with a typical thyroglossal duct cyst and underwent surgical resection of the cyst, which was determined to be follicular carcinoma. We have reported this rare case to increase the awareness of such entities within the general otolaryngology and the community of head and neck surgeons, as well as among endocrine surgeons.