Endocrine Abstracts

JOINT3591

Introduction: The management of thyroid nodules in children is challenging. Moreover, the risk of malignancy for any nodule is higher than in adults.

Aim: To assess the subtypes of cancer in thyroid nodules in a pediatric population and to observe their clinical evolution.

Material and Methods: We retrieved from our endocrinology center database all the fine-needle aspiration (FNA) procedures and all the pathology results from total/subtotal thyroidectomies performed on < 18-year old children between January 2020 and June 2024.

Results: There were 163 patients, of whom 39 (23. 92%) had thyroid malignancies. Of the 39 patients, the mean age at diagnosis was 14. 66 years (youngest -7, oldest – 18), with a girls/boys ratio – 33/6. 19 of them had preoperative FNA procedures: there were 4, 6 and 9 patients with Bethesda 4, 5 and 6 respectively. 35 patients had papillary thyroid carcinoma (PTC), 1 follicular carcinoma (FC) and 3 medullary thyroid carcinoma (MTC). Of the 35 patients with PTC, 17 had diffuse sclerosing PTC (48. 57%), 12 classic PTC (35. 29%), 2 follicular variant PTC (5. 88%), 2 trabecular PTC (5. 88%), 1 tall cell PTC (2. 94%) and 1 Warthin tumor (2. 94%). 18 (50%) and 3 (8. 33%) patients had cervical lymph node and pulmonary metastases respectively at diagnosis. The majority of patients with PTC (41. 66%) had an excellent biochemical and structural response after surgery and radioiodine therapy (RAI). Of the 3 patients with CMT, 2 of them had positive RET mutations for MEN 2A, and familial CMT, but unfortunately did not undergo prophylactic thyroidectomy, and only got surgery when calcitonin levels were already elevated and the thyroid tumor was detectable on ultrasound. The other patient had a positive de novo RET mutation (Met918), underwent 3 surgical interventions, and still has signs of residual disease and elevated calcitonin levels (400 mg/dl). None of the patients have had a thyroid carcinoma related death.

Conclusion: The most common type of carcinoma in these patients was diffuse sclerosing PTC (43. 58%). The clinical evolution of these patients varies according to malignancy subtype, the majority of them having a good clinical outcome. Children with familial MTC and positive RET mutations need better clinical monitoring and appropriate therapeutic intervention.