Upper neck papillary thyroid carcinoma: a case report

Background: Upper neck papillary thyroid carcinoma (UPTC) encompasses thyroglossal duct cyst carcinoma (TGDCC), pyramidal lobe papillary thyroid carcinoma (PTC), and Delphian node metastasis. TGDCC, a rare malignancy, occurs in less than 1% of TGDCs, with papillary carcinoma being the predominant subtype. Accurate diagnosis and management of TGDCC are challenging due to its overlapping features with other UPTC subtypes. Case presentation: A 30-year-old South Asian male presented with a painless midline neck swelling for 1 year and a right submandibular swelling for 3 months. Ultrasound and contrast-enhanced CT revealed a midline cystic lesion with calcifications, consistent with a TGDC, and a benign submandibular cyst. The patient underwent a Sistrunk procedure along with the submandibular cyst excision and Level 1B neck dissection. Discussion: TGDCC typically presents as a painless midline neck swelling, with over 90% of cases being papillary carcinoma. Ultrasound is the initial imaging modality, and fine-needle aspiration has limited diagnostic accuracy. The Sistrunk procedure is the standard treatment for TGDCC, but the high incidence of concurrent thyroid malignancy (20%-62%) prompts debate over routine thyroidectomy. For low-risk TGDCC patients (under 45, no lymph node involvement, negative margins), the Sistrunk procedure alone may suffice, with annual surveillance recommended if thyroidectomy is not performed. Conclusion: This case underscores the utility of the UPTC classification in distinguishing TGDCC from other subtypes, guiding precise surgical intervention. The Sistrunk procedure effectively managed low-risk TGDCC, with ongoing surveillance essential to monitor for recurrence or thyroid malignancy.