Case report: ectopic papillary thyroid carcinoma found in the midline of the hyoid bone and cervical lymph nodes, no thyroid lesions.

BACKGROUND

Ectopic thyroid tissue (ETT) is primarily caused by embryonic dysplasia. It is commonly located laterally in the neck or in the thyroglossal duct, as well as in more remote locations like the mediastinum and the subdiaphragmatic organs. The incidence of ETT is relatively rare, and the risk of malignant transformation is extremely low. The clinical symptoms of ETT are typically linked to the site of ETT involvement, and histopathological or biopsy examination is typically used to confirm the diagnosis of ectopic thyroid cancer.

CASE DESCRIPTION: We present a rare case of a 30-year-old woman with a mass in the neck, who was otherwise asymptomatic. Relevant examinations were performed before the surgery. However, a diagnosis of ectopic papillary thyroid carcinoma (PTC) with metastases in the lateral cervical lymph nodes was confirmed.

CONCLUSIONS

An excision of the anterior cervical mass and a lateral cervical lymphadenectomy were performed. Postoperative pathology revealed PTC in the anterior neck mass, with metastases to the lateral cervical lymph nodes. This case shows that thyroid cancer can originate from ectopic tissue, even when no thyroid lesions are present. Thus, early and accurate identification are essential to optimize the diagnosis and clinical treatment of ETT.