Endocrine Abstracts

Introduction: Hashimoto’s thyroiditis (HT) is the most frequent cause of thyroid disfunction in children and its incidence is increasing. Although thyroid cancer is an uncommon childhood malignancy with a reported incidence of about 0.59 cases per 100,000, there are data suggesting the comorbidity of papillary thyroid carcinoma with autoimmune thyroiditis (AIT) in children. Ultrasound elastography is a non-invasive imaging, based on estimation of mechanical properties (elasticity) of the tissue, improving the differential diagnosis of thyroid nodules. In our study we aimed to determine the elastographic features of thyroid nodules in children and adolescents with AIT and nodular goiter in relation to cytological and/or histopathological diagnosis and to assess if the autoimmune process reduces the accuracy of elastography in nodule evaluation.

Materials and Methods: We examined 215 children (57 boys and 158 girls) with 261 thyroid nodules (143 non-AIT and 118 AIT) between February 2013 and September 2021. All patients underwent conventional ultrasound with elastography followed by fine needle aspiration biopsy (FNAB). Elastography parameters were acquired with Toshiba Aplio MX SSA-780A system and analyzed while comparing of the stiffness of the nodule (ROI 1) to the healthy tissue (ROI 2).

Results: Abnormal Strain Ratio (SR ≥ 5) was observed in 36 non-AIT nodules and 15 AIT nodules. Papillary thyroid carcinoma was diagnosed in 5 patients (2% of all investigated nodules), these were 3 non-AIT nodules and 2 AIT nodules. SR of malignant thyroid nodules was statistically higher than benign ones both in the group of non-AIT (6±4 vs. 3.67±2.62, P=0.024) and AIT nodules (6.3±0.01 vs. 2.92±1.89, P=0.047). Comparing non-AIT and AIT benign nodules SR was higher in non-AIT nodules (3.67±2.62 vs. 2.92±1.89, P=0.01). The sensitivity and specificity of elastography for detecting malignant nodules in non-AIT was 67% and 76% respectivey and in AIT nodules 100% and 88% respectively. Elastography’s NPV was 99% in non-AIT nodules and 100% in AIT nodules.

Conclusions: Autoimmune inflammatory process of the thyroid gland does not limit the use of elastography in the diagnosis of thyroid nodules in children.