Endocrine Abstracts

Background: Thyroid nodule in the pediatric age group is rare, but the rate of malignancy is much higher than adult population. Fine needle aspiration biopsy (FNAB) is an accurate test commonly used to determine whether thyroid nodules are malignant in adults. However, less is known about its diagnostic accuracy for this purpose in children.

Aim: To characterize the outcomes of FNAB of nodular thyroid disease at a pediatric tertiary-care institution and to correlate cytopathology with histopathology.

Materials and methods: Retrospective analysis to identify children who underwent FNAB of the thyroid between 2000 and 2016. Epidemiological, clinical, radiological, cytologic and histopathologic data were analysed. The smears were categorized according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) into six categories – Nondiagnostic, benign, atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), suspicious for follicular neoplasm (SFN), suspicious for malignancy (SM), and malignancy.

Results: Out of 32 cases, 87.5% were females. Patients ranged in age from 6.8 to 17.9 years (mean±S.D., 14.8±2.6 years). Seven individuals underwent more than one FNAB. Histological follow-up was available in 50%cases. The diagnosis according to TBSRTC included 3 (9.4%) nondiagnostic, 22 (68.8%) benign, 1 (3.1%) AUS/FLUS, 0SFN, 2 (6.3%) SM, and 4 (12.5%) malignancy cases. On histological follow-up (n=16), the rate of malignancy was 50%.There was no difference in the ecografic size of the nodule of benign versus malignant lesions (P=0.27) or diagnostic versus non-diagnostic lesions (P=0.61). No difference was found in benign versus malignant lesions (P=0.97) or diagnostic versus non-diagnostic lesions (P=0.60), concerning mean age. Diagnoses at cytopathology and surgical pathology were concordant in 9/14 (64%) nodules. Overall sensitivity of FNAB was 66.7% and specificity was 75%.

Conclusion: Due to the limited sample size our FNAB sensitivity and specificity are lower than the previous reported on literature (90.6–100% and 76.2–100%, respectively). In patients whose cytology was reported as inadequate or benign, is important to maintain follow-ups.