Research progress of ectopic thyroid cancer in thyroglossal duct cyst: A case report and literature review

Abstract

Rationale: Thyroglossal duct carcinoma, a rare clinical condition characterized by ectopic thyroid adenocarcinoma within thyroglossal duct cysts (TGDCs), typically confirmed through intraoperative rapid pathology, this condition generally has a favorable prognosis. Nevertheless, comprehensive treatment guidelines across all disease stages are lacking, the purpose of this study is to report 1 case of the disease and propose the treatment plan for each stage of the disease.

Patient concerns: A patient presented with thyroid swelling, classified as C-TIRADS 4A following a physical examination. Preoperative thyroid puncture identified papillary thyroid carcinoma, and genetic testing revealed a BRAF gene exon 15-point mutation. Ancillary tests showed a slightly decreased thyroid stimulating hormone (TSH) level (0.172) with no other significant abnormalities.

Diagnoses: Preoperative fine-needle aspiration cytology (FNAC) confirmed right-side thyroid cancer. Intraoperative exploration uncovered a TGDC and intraoperative rapid pathology confirmed thyroglossal duct carcinoma.

Interventions: A Sistrunk operation and ipsilateral thyroidectomy were performed.

Outcomes: Postoperative recovery was satisfactory.

Lessons: Thyroglossal duct carcinoma is a rare disease affecting the neck. Due to limited clinical cases and the favorable prognosis associated with this condition, there is currently no established set of diagnostic and treatment guidelines. According to tumor size, lymph node metastasis, thyroid status and other factors, the corresponding treatment methods were established for each stage of thyroglossal duct cancer, which laid the foundation for the subsequent treatment development of this disease.

Figure 1.

(A) Ultrasound of the left lobe of the thyroid gland showing a lower-middle mass with a regular shape and clear margins. (B) Ultrasound of the right lobe of the thyroid gland showing a lower mass with indistinct borders, irregular shape and internal calcified spots.

Figure 2.

Gross observation of thyroglossal duct cancer after nanocarbon tracing (The part in the red box is the right lobe of the thyroid gland, the part in the blue box is thyroid duct cancer, and the remaining 2 are divided into thyroid tissue and lymph nodes).

Figure 3.

HE (100×) stained section of thyroglossal duct cancer.

Figure 4.

Thyroglossal cyst diagnosis and treatment flowchart.