The CT appearance of thyroglossal duct carcinoma

Thyroid carcinoma arising in a thyroglossal duct cyst may be clinically indistinguishable from a benign thyroglossal duct cyst. The preoperative diagnosis of carcinoma, however, can have important implications for surgical planning and postoperative treatment. Our purpose was to describe the CT appearance of thyroglossal duct carcinoma and identify the features that distinguish thyroglossal duct carcinoma from benign thyroglossal duct cysts.

Retrospective review of the medical records from the University of Pittsburgh Medical Center and Geisinger Medical Center (Danville, Pennsylvania) identified six patients with papillary thyroid carcinoma within the thyroglossal duct who had undergone preoperative CT examinations of the neck. There were two women and four men. Their ages ranged from 14 to 59 years. Three patients underwent contrast-enhanced CT of the neck, and three underwent unenhanced CT. All CT examinations consisted of 3- to 5-mm-thick contiguous axial sections.

Each patient had an anterior neck mass with a cystic component. Two of the masses had dense or enhancing mural nodules, two had irregular calcification throughout the mass, and two had dense or enhancing mural nodules with additional foci of calcification. One patient had cervical lymphadenopathy.

Carcinoma should be considered in thyroglossal duct cysts that have a mural nodule or calcification or both.