Retropharyngeal Ectopic Papillary Thyroid Carcinoma Coexisting with Orthotopic Goiter: A Rare Case Report

Ectopic thyroid carcinoma is rare. We present an exceptionally rare case of primary retropharyngeal ectopic papillary thyroid carcinoma (PTC) coexisting with an orthotopic thyroid goiter, aiming to enhance clinical awareness of this condition and to emphasize the importance of comprehensive management of both the ectopic lesion and the orthotopic thyroid.

Case report and literature review.

A 29-year-old male with a 3-year history of pharyngeal foreign body sensation underwent laryngoscopy and noncontrast CT/MRI, revealing a 2.0 × 3.5 cm left retropharyngeal mass. The mass was confirmed as papillary carcinoma via transoral excision. Postoperative contrast-enhanced CT identified metastatic-level VI lymphadenopathy, prompting total thyroidectomy with central neck dissection. Histopathology verified ectopic PTC with central node metastasis (1/20 nodes). Orthotopic thyroid exhibited nodular goiter without malignancy. No recurrence was observed during 36 months of follow-up.

This case highlights retropharyngeal ectopic PTC's diagnostic complexity in a patient with orthotopic thyroid gland. Management of ectopic thyroid carcinoma may be guided by thyroid carcinoma guidelines, given its rarity. Total thyroidectomy is recommended to exclude concurrent thyroid malignancy and enable thyroglobulin-based surveillance.