Metastatic Papillary Thyroid Carcinoma Arising from Thyroglossal Duct Cysts

ABSTRACT Objective: We report a rare case of a patient who developed papillary thyroid carcinoma (PTC) arising from thyroglossal duct cysts (TGDCs) with lateral lymph node metastasis who had a normal thyroid gland and benign central compartment lymph nodes. Methods: We present a case with metastatic PTC arising from TGDC together with a brief review of the relevant literature. Results: A 38-year-old man patient was admitted with a cystic lesion in the midline of his neck. There was also an easily palpable lymph node on the left neck, which was suspected of being metastatic PTC on ultrasonography (USG). There was no nodule in the thyroid gland. A fine-needle aspiration cytology of the lymph node was positive for metastases of PTC. We performed an excision of the cystic lesion and total thyroidectomy with the central and left neck lymph node dissection. The cystic lesion pathology was reported as PTC, 10 mm in size. There was a metastatic lymph node in the lateral left neck compartment (regions III–IV), 7 cm in diameter, without central lymph node involvement. Radioactive iodine ablation therapy with 150 mCi of 131I was given after the surgery. The patient is in remission for PTC 2 years after his surgery, and he is currently receiving levothyroxine suppression therapy. Conclusion: While evaluating a TGDC, a detailed neck USG should be performed in all cases. Furthermore, a biopsy should be conducted of suspected lymph nodes before planning the surgery. Abbreviations: DTC = differentiated thyroid cancer; FNA = fine-needle aspiration; MRI = magnetic resonance imaging; PTC = papillary thyroid carcinoma; RAI = radioactive iodine ablation; TGD = thyroglossal duct; TGDC = thyroglossal duct cyst; USG = ultrasonography