Ectopic Papillary Thyroid Carcinoma of the Posterior Pharynx

Ectopic thyroid is an uncommon condition resulting from the aberrant development of the normal thyroid gland and is usually found along the thyroglossal tract: lingual, submandibular, thyroglossal cysts, intra-tracheal and mediastinal, or, on rare occasions, in the adrenal gland, gallbladder, gastrointestinal tract, pancreas, and struma ovarii.

We describe a novel case where primary papillary thyroid carcinoma (PTC) was found after a trans-oral excision of a tumor containing ectopic thyroid tissue at the posterior pharynx, an area not known to be a location for ectopic thyroid. Delays due to the COVID-19 pandemic resulted in regional cervical metastases and multifocal PTC. The female patient successfully underwent total thyroidectomy, selective cervical and central lymph node dissection, followed by adjuvant radioactive iodine ablation, with no evidence of distant metastases.

Ectopic thyroid tissue is uncommon and may be in the posterior pharynx. The principles of management remain those of differentiated thyroid malignancy: complete surgical resection of any tumor focus, total thyroidectomy, and node dissection of involved lymph nodes, followed by adjuvant radioactive iodine in iodine-sensitive tumors.