Papillary Thyroid Carcinoma Within Thyroglossal Duct Cyst

A 55-year-old female with medical history of hypothyroidism and fibrocystic disease of the breast presented with complains of a painful anterior neck mass, difficulty swallowing and hoarseness of the voice. Symptoms had progressed over a period of 5 months. CT neck with contrast indicated the presence of an ectopic thyroid tissue anterior to the thyroid cartilage measuring approximately 1.7 x 1.2 x 3.1 cm, with indistinct inferior margins and internal calcifications. The hyoid bone or thyroid cartilage had no irregularities. The thyroid gland itself was unremarkable except for small complex thyroid nodules in both lobes. No masses within the pharynx or larynx were noted. Family history was significant for lymphoma in her father. On physical exam, a hard, mobile right anterior neck mass was appreciated. Labs showed normal TSH of 1.05 uIU/mL and normal free T4 of 1.2 ng/dL. Further evaluation with a dedicated neck US showed a right submandibular mass, superior to the thyroid, lobulated and heterogeneous measuring 2.0 x 1.0 x 2.3 cm with multiple areas of calcifications and internal Doppler flow. The thyroid gland had normal size and texture with bilateral sub centimeter non-concerning nodules. After ENT evaluation and an unremarkable flexible fiberoptic nasolaryngoscope, patient underwent surgical excisional biopsy of the neck mass. Pathology was consistent with thyroglossal duct cyst with the presence of thyroid follicles. An incidental finding of a 0.9 cm papillary microcarcinoma was noted, which was encapsulated with focal extracapsular follicular structures showing papillary nuclear features with no perineural or lymphovascular invasion. The tumor cells were immunoreactive for TTF-1 and PAX8. Development of papillary thyroid cancer within the thyroglossal duct cyst is a rare event, reportedly occurring in 1% of thyroglossal duct cysts. There are no well-established management guidelines. Current management strategies consist of monitoring with serial neck ultrasound versus total thyroidectomy with consideration of postsurgical I-131 treatment, based on pathology results. Our patient opted for undergoing total thyroidectomy.