Hürthle Cell Carcinoma Arising in a Thyroglossal Duct Cyst.

Thyroglossal duct carcinoma is a rare clinical condition, accounting for only 1% of operated cases. It is characterized by ectopic thyroid adenocarcinoma developing within thyroglossal duct cysts (TGDCs). Among these, papillary thyroid carcinoma is the most frequently reported pathological type. The clinical presentation of thyroglossal duct malignancies is often nonspecific, with diagnosis typically confirmed postoperatively via the Sistrunk procedure. Due to the rarity of these cases and their generally favorable prognosis, standardized diagnostic and treatment guidelines have not yet been established. We report a rare case of a 31-year-old patient who underwent surgery for an anterior neck mass that had developed over the years. Histopathological examination revealed a Hürthle cell carcinoma occurring in a thyroglossal duct remnant. Following this diagnosis, the patient underwent a total thyroidectomy. The postoperative management plan included radioactive iodine therapy and thyroid hormone suppressive therapy.