Thyroid Cancer Arising from Thyroglossal Duct Cyst

Purpose: Thyroglossal duct cyst is the most common congenital anomaly of the neck, and malignancy arising from a thyroglossal duct cyst occurs only in approximately 1% of patients. Ultrasound examination and fine-needle aspiration should be performed to make an accurate diagnosis before surgery. Sistrunk operation is known as a surgical treatment for thyroglossal duct cyst. We describe the clinical characteristics of thyroglossal duct cyst carcinoma in eight cases and the treatment methods for each. Methods: This is a retrospective study of thyroglossal duct cyst detected in patients undergoing surgery at two separate tertiary medical institutions in Korea from July 2006 to August 2020. Results: Among 346 patients with thyroglossal duct cyst, eight were diagnosed with thyroglossal duct cyst carcinoma. In four out of these eight patients, cysts and thyroid nodules were observed, and thyroidectomy and Sistrunk operation were performed together. Modified radical neck dissection was performed only in two patients with confirmed lymph node metastasis before surgery. All four patients who underwent total thyroidectomy and Sistrunk operation received radioactive iodine treatment and did not receive radiation therapy. None of the patients had distant metastasis. Conclusion: Thyroglossal duct cyst carcinoma is rare, and an initial evaluation is critical in determining the extent of surgery. Fine needle aspiration should be performed in patients who are clinically diagnosed with thyroglossal duct cyst, and a thyroid ultrasound scan should also be performed.ope