Abstract

Background: Thyroglossal duct cyst (TDC) is a congenital cyst with an incidence of about 7%. Thyroglossal duct cyst carcinoma (TDCC) is a rare complication that arises from TDC, with an incidence of about 1%. Papillary thyroid carcinoma is the most common histological subtype.
Case presentation: A 55-year-old female patient presented with a midline neck swelling with a discharging sinus. Ultrasound demonstrated a TDC with thick septa and clumps of calcification in the submental region. A well-defined hypoechoic elliptical lesion was seen at the border of the isthmus and right thyroid lobe measuring 8.4 mm. Sistrunk procedure was carried out initially, which revealed papillary thyroid carcinoma arising in a TDC. Subsequent thyroidectomy and radioiodine evaluation were performed. Nuclear medicine findings and follow-up outcomes have been described in the case report.
Conclusion: Thyroglossal duct carcinoma is uncommon and requires a multidisciplinary approach. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer have included new recommendations regarding this entity, which were not present in the 2015 ATA guidelines. Recommendations regarding surgical approaches, post operative risk stratification, radioiodine diagnostic imaging, therapy, and follow-up of these patients have been established, and the described case was managed accordingly.

Key words: Keywords: Thyroglossal duct cyst, papillary thyroid carcinoma, Radioiodine, Sistrunk, Total thyroidectomy, ATA DTC guidelines