“Predictive Factors of Malignancy in Pediatric Patients with Thyroid Nodules and Performance of the Italian Classification (SIAPEC 2014) in the Outcome of the Cytological FNA Categories”

Abstract

Purpose: The rate of malignancy (ROM) among pediatric studies using the Bethesda System is 39.5% and 41.5% for atypia of undetermined significance/follicular lesion of undetermined significance and for suspected follicular neoplasm, respectively. Data reported on the basis of Bethesda System system showed lower ROM in adults with indeterminate nodules (30.5% and 28.9% respectively). Studies on adults based on the Italian Society of Anatomic Pathology and Cytology (SIAPEC) classification, report ROM of 14.2 % for TIR3a and 44.6% for TIR3b category, showing greater sensitivity in detecting malignancy. To date, no performance data are available about SIAPEC classification in pediatric age.Methods: retrospective data were collected from 200 pediatric subjects with thyroid nodules in the period 2000-2020.Results: The distribution of cytological categories after fine needle aspiration biopsy (FNAB) was 7 TIR1, 4 TIR1c, 22 TIR2, 14 TIR3a, 9 TIR3b, 3 TIR4 and 16 TIR5. Surgical approach was performed in 40/200 subjects, with total ROM of 65% (0% for TIR1-TIR3a, 77.8% for TIR3b and 100 % for TIR4-TIR5). Total FNAB accuracy was 95%, while the sensibility and specificity were 92.3% and 92.6%, respectively. Conclusions: The reported data seem to confirm a greater sensitivity of SIAPEC classification to identify malignancy within the indeterminate category also in pediatric age and not only in adulthood. This finding may orient clinicians towards clinical follow-up for the indeterminate TIR3a group and towards surgical approach with total thyroidectomy in the indeterminate TIR3b group, although this indication should be confirmed in further national multicenter studies including larger cohorts.

Evaluation of the efficacy of EU-TIRADS and ACR-TIRADS in risk stratification of pediatric patients with thyroid nodules

“…Other features include intranodal calcification or vascularization, lymph node involvement, marked hypoechoic pattern, bilateral or right lobe localization of the nodule, poorly defined nodule margins and some clinical risk factors, particularly radiation exposure for cancer treatment, increased TSH values, young age and male gender. In our cohort, TSH levels were correlated to malignancy, as previously reported (6,26). Considering the child's body size and the presence of microcarcinomas, in presence of multiple risk factors FNAB should be performed even if the nodule size is smaller than 1 cm (1-7).…”

“…The cytological category assignment leads to different clinical management that includes clinicalradiological follow-up or surgery, with some differences between these classifications. Despite the differences, all agree on a higher ROM in paediatric age for all categories, especially for indeterminate nodules (6,33,34).…”

“…Nodular thyroid disease in paediatric age has a lower prevalence (0.2-5.1%) than in adulthood (1-10%) (1-3), but the main difference between paediatric and adult age lies in the rate of malignancy (ROM) (16-26% vs 5-10%) (4)(5)(6). The most important risk factors for the development of thyroid cancer include underlying thyroid disease, radiation exposure, previous malignancy, family history, young age, male gender, and genetic predisposition .…”