Endocrine Abstracts

JOINT2659

Introduction: Thyroglossal duct cyst (TGDC) is the most frequent cervical congenital anomaly. Thyroid carcinomas arising from these structures are rare, being present in approximately 1.5% of patients with TGDC. The diagnosis usually is done post-operatively after the resection of the cyst. Due to the rare occurrence there is no definite consensus on the optimal treatment of thyroid cancer in thyroglossal duct cyst carcinomas (TGDCCs), namely the need of complementary thyroidectomy.

Objective: We aimed to assess tumor presentation, therapeutic strategy and follow-up in a series of patients with TGDCCs.

Methods: We performed a retrospective analysis of all patients with TGDCCs, selected from the pool of individuals with histological diagnosis of thyroglossal duct cyst established between 2010 and 2024 at our institution.

Results: From a total of 244 patients with thyroglossal duct cysts, 7 patients (2.9%) were identified with TGDCCs (5 females, 2 males), aged at diagnosis between 17 and 65 years (mean: 41,1; median: 41). In six patients clinical presentation was a cervical mass while the other was diagnosed by an ultrasound scan during follow up of a previous thyroid cancer. In all cases the diagnosis was established after surgery. Papillary thyroid carcinoma (PTC) was found in all samples (follicular variant PTC in 1 patient and classic PTC in 6 patients), sized between 0.1 and 1.4 cm, 5 of them being microcarcinomas. All patients were treated with Sistrunk surgery; one did total thyroidectomy at the same time for a suspicious nodule that histology confirmed as synchronous PTC with vascular invasion and was treated with radiodine ablation; the other two did a complementary thyroidectomy afterwards, both with no malignancy. None of the cases presented capsular invasion, lymphovascular invasion, soft tissue extension, lymph node metastasis or positive margins. No metastasis or recurrence was found in any of the cases after a mean follow up of 8.6 (4-14) years.

Conclusion: TGDCCs are a rare clinical entity with good prognosis. Despite the controversy regarding their therapeutic approach and follow-up, Sistrunk procedure alone with regular thyroid evaluation may be enough in low-risk patients. Further studies are needed to clarify this issue.