Papillary carcinoma Arising in Thyroglossal duct cyst â" A case report in perspective of 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer
Abstract
Topic: Papillary carcinoma Arising in Thyroglossal duct cyst â" A case report in perspective of 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer Author: Dr. Hira Tahir, NM and PET-CT department, INMOL, Lahore 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 which arises from TDC, with an incidence of about 1%. Papillary thyroid carcinoma is the most common histological subtype. Case presentation: A 55 years old female patient presented with a midline neck swelling with a discharging sinus. Ultrasound demonstrated thyroglossal duct cyst with thick septa and clumps of calcification in submental region. A well-defined hypoechoic elliptical lesion was seen at border of isthmus and right thyroid lobe measuring 8.4 mm. Sistrunk procedure was carried out initially which revealed papillary thyroid carcinoma arising in thyroglossal duct cyst. 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 previously were not present in 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. Keywords: Thyroglossal duct cyst, papillary thyroid carcinoma, Radioiodine, Sistrunk, Total thyroidectomy, ATA DTC guidelines â Introduction The thyroid gland originates from a median endodermal thickening in the floor of the primitive pharynx at the foramen cecum between first and second pharyngeal arches. During the fourth week of gestation the thyroid primordium descends from the tongue base to its final position in the neck via a narrow epithelial tract called thyroglossal duct. The duct normally involutes and disappears by the tenth week of gestation [1]. Persistence of any part of thyroglossal duct can lead to cyst, sinus, fistula, ectopic thyroid tissue along the tract and rarely thyroglossal duct carcinoma. Thyroglossal duct cyst (TDC) is a common congenital cyst with an incidence of about 7%. Thyroglossal duct cyst carcinoma (TDCC) is a rare complication which arises from TDC, with an incidence of about 1%. Papillary thyroid carcinoma is the most common histological subtype (80-90%) followed by follicular carcinoma (5-10%), squamous cell carcinoma (<5%). Other rare subtypes including Hurthle cell, anaplastic and adenocarcinoma have also been reported [2]. Being a rare entity, it requires a multidisciplinary approach in management. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer are the first ATA guidelines to specifically address thyroglossal duct carcinoma [3] [4]. Case Presentation 55 years old female patient presented with history of a midline neck swelling with a discharging sinus one year back. Ultrasound neck demonstrated well defined thick walled multi-septated multilobulated cystic lesion with thick septa and clumps of calcification in submental region, measuring approximately 5 x 4 cm showing minimal flow on color Doppler peripherally. No communication with major neck structures was seen. Bilateral thyroid lobes were normal sized approximately 2 x 2 cm each. A well-defined hypoechoic elliptical lesion was seen at border of isthmus and right thyroid lobe measuring 8.4 mm. Both parotid and submandibular glands were unremarkable, No cervical lymphadenopathy was seen on either side. Sistrunk procedure was carried out. Drain was inserted po