The CT appearance of thyroglossal duct carcinoma

BACKGROUND AND PURPOSE: Thyroid carcinoma arising in a thyroglossal duct cy st may be clinically indistinguishable from a benign thyroglossal duct cyst . The preoperative diagnosis of carcinoma, however, can have important impl ications 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 thyro glossal duct cysts. METHODS: Retrospective review of the medical records from the University of Pittsburgh Medical Center and Geisinger Medical Center (Danville, Pennsylv ania) identified six patients with papillary thyroid carcinoma within the t hyroglossal 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 under went unenhanced CT. All CT examinations consisted of 3- to 5-mm-thick conti guous axial sections. RESULTS: Each patient had an anterior neck mass with a cystic component. Tw o of the masses had dense or enhancing mural nodules, two had irregular cal cification throughout the mass, and two had dense or enhancing mural nodule s with additional foci of calcification. One patient had cervical lymphaden opathy. CONCLUSION: Carcinoma should be considered in thyroglossal duct cysts that have a mural nodule or calcification or both.