IMPE Abstracts

Introduction: Thyroid cancer is a rare disease in children. Malignancy should be suspected in the presence of non-infectious cervical adenopathy, a palpable thyroid nodule, or an asymmetric thyroid gland. Risk factors associated with developing follicular thyroid cancer include autoimmune thyroid disorders, iodine deficiency, and prior exposure to radiation.

Case report: A 6-year-old male patient was evaluated at the pediatric endocrinology outpatient clinic at the Albert Sabin Children's Hospital due to hyperthyroidism diagnosed at 3 years of age and using Tapazol 15mg/day. Tests were performed: TSH 1.18 U/ml, free T4 0.59 ng/dl, anti-TPO, anti-thyroglobulin and TRAB negative and thyroid US: echogenic nodule 1.6 x 1.2 cm in the upper 1/3 of the left lobe with central and peripheral vascularization and a 0.9x0.5 cm mixed cystic nodule in the lower 1/3 of the right lobe. After 6 months, a repeat Doppler US of the thyroid was performed, with a 2x1.7 cm nodule in the left lobe with peripheral vascularization (Flames III) and signs of diffuse thyroidopathy, and tests showed hyperthyroidism. The dose of tapazol was increased to 20mg/day and a scintigraphy was performed, which showed a focal area with increased uptake in the lower third of the left lobe, with the remainder of the left lobe with reduced uptake. A hypothesis of hyperthyroidism due to toxic nodular goiter was raised and a fine-needle aspiration (FNA) puncture was performed in the left thyroid nodule evidenced by Bethesda III. A new US showed a 2.7x1.8x2.2 cm nodule in the left lobe, heterogeneous, solid, well delimited, without microcalcifications. The child underwent partial left thyroidectomy and intraoperative frozen section biopsy was performed, compatible with follicular neoplasia and histopathological findings that showed minimally invasive follicular carcinoma. After 2 months, the patient returns to the outpatient clinic asymptomatic, with TSH < 0.01 U/ml and free T4 4.13 ng/dl. Tapazole 20 mg/day is restarted and total thyroidectomy is indicated. Histopathological examination showed multinodular colloid goiter. The patient maintains regular follow-up with clinical and laboratory evaluation.

Conclusion: Toxic adenoma is a common cause of hyperthyroidism in adulthood, being a rare etiology in childhood. Due to its low prevalence, a more comprehensive investigation is necessary due to the increased risk of malignancy. In the presence of hyperthyroidism with negative TRAB and a nodule evidenced on US, scintigraphy, FNA and the need for surgical resection should be evaluated.