SAT574 Thyroglossal Duct Papillary Thyroid Cancer With Normal Eutopic Thyroid Gland: A Management Dilemma

Disclosure: H. Belal: None. J.T. Batch: None. G.Y. Gandhi: None. Background: The incidence of thyroglossal duct cyst carcinomas is less than 1%, the majority being papillary thyroid cancer. One-third arise de novo from the thyroglossal duct. The rest are direct metastasis of eutopic papillary thyroid cancer. Management in the setting of a normal eutopic thyroid gland is challenging. Clinical Case: A 35-year-old female presented with transient right facial paresthesia. CT angiogram revealed an incidental 2.3 cm thyroglossal duct cyst with internal ectopic thyroidal tissue and micro-calcifications. She denied any compressive symptoms, radiation exposure, or family history of thyroid cancer and was euthyroid. Ultrasound noted a normal thyroid gland and complex solid-cystic mass measuring 2.3 x 2.0 x 1.5 cm superior to the isthmus. Satisfactory fine needle aspiration of the mass revealed benign-appearing epithelial cells, macrophage, and colloid-like material. Due to new anterior neck pain, a Sistrunk Procedure (SP) was performed. Pathology revealed a 1.2 cm papillary thyroid carcinoma, conventional type (confirmed by TTF-1 and thyroglobulin stains), arising within the thyroglossal duct cyst. Surgical margins were free of cancer, and there was no lymphovascular invasion. A thyroid ultrasound seven months after the procedure revealed heterogenous thyroid tissue, no thyroid nodules, and several small benign-appearing reniform-shaped cervical lymph nodes in zones 1 and 2. The patient was offered yearly thyroid ultrasound surveillance versus prophylactic thyroidectomy. She elected to proceed with thyroidectomy due to concerns about disease recurrence. Final pathology results revealed right lobe 2 mm papillary microcarcinoma limited to the thyroid. Conclusion: Fine needle aspiration of thyroglossal duct cysts can have a high false negative rate, as in our patient. There is currently no consensus on treatment of thyroid carcinomas arising from thyroglossal duct cysts. There are four possible surgical strategies: 1) SP alone 2) SP with concurrent thyroid lobectomy or pyramidal lobe resection 3) SP with total or near total thyroidectomy in all patients and 4) SP and selective addition of total or near total thyroidectomy in high-risk patients. The role of radio-iodine ablation and levothyroxine suppression after SP is also unclear. Management recommendations are Grade C, relying on case reports, case series, and expert opinion. Whether or not to proceed with total thy