Histologic and Clinical Follow-up of Thyroid Fine Needle Aspirates in Pediatric Patients

Abstract

BACKGROUND Although fine-needle aspiration (FNA) has an important role in evaluating thyroid nodules in adults, there is little published information regarding its utility in the pediatric population. METHODS A retrospective analysis of thyroid FNAs for patients who were 18 years old or younger at 2 institutions was conducted. Aspirates were retrospectively categorized with the Bethesda System for Reporting Thyroid Cytopathology. These diagnoses were then correlated with either final histopathology or clinical follow-up. RESULTS A total of 186 thyroid FNA samples from 154 patients (122 females and 32 males), who ranged in age from 9 months to 18 years (median, 16 years; mean, 14 years), were identified. FNA was performed to evaluate 1 to 3 nodules for each patient. Aspirates were classified as follows: nondiagnostic (n = 27), benign (n = 114), atypia of undetermined significance (AUS; n = 21), follicular neoplasm (FN; n = 8), suspicious for malignancy (n = 3), and malignant (n = 13). Sixty-one samples had a histologic correlation, 68 were followed clinically for ≥2 years, and 57 either had no follow-up or were followed for <2 years. For statistical purposes, FNA diagnoses of suspicious and malignant were considered positive, and benign lesions were considered negative. The accuracy was 99%, and the sensitivity and specificity were 94% and 100%, respectively. The risk of malignancy, not including papillary microcarcinoma, was 2% for benign aspirates, 21% for AUS, 57% for FN, and 100% for suspicious or malignant aspirates. CONCLUSIONS This analysis demonstrates that FNA is a sensitive and highly specific modality for evaluating thyroid nodules in pediatric patients. Each diagnostic category can facilitate communication and guide appropriate management.