Thyroid fine needle aspiration cytology in children and adolescents.

Thyroid fine needle aspiration cytology (FNAC) is the most accurate and cost effective method in the evaluation of the thyroid nodule and has been commonly used in adults. Thyroid nodules are uncommon in younger patients (1-2%). Our aim was to determine some relevant clinical and cytological parameters in this demographic group. Ultrasound-guided thyroid FNACs performed from May 1995 to June 2008 in patients under 18 years of age were retrospectively reviewed. The following clinical parameters were retrieved: age and gender, number of nodules, and nodule size. Cytological parameters included cytologic diagnosis and cyto-pathohistological correlation. Total of 236 cases, representing 206 patients under 18 years of age, were retrieved from a total of 11748 thyroid FNAC cases (2.0%). The patient's age ranged from 2 to 18 years (mean 14). There were 180 (87.4%) females and 26 (12.6%) males with a female/male ratio 4:1. For 56 patients data concerning the number of nodules were recorded. 20 (35.7%) patients did not have any nodules, 20 (35.7%) patients had solitary thyroid nodule and 16 (28.6%) patients had multiple nodules. The size of nodules ranged from 0.4-5.4 cm (mean 1.4 cm). The cytologic diagnoses were: unsatisfactory (9), cyst fluid (7), benign (204), cellular follicular lesion/follicular neoplasm (9) and papillary thyroid carcinoma (7). The prevalence of malignancy among cytologic diagnoses was 3.4%. 21 patients had surgical follow up. 5 patients (23.8%) had thyroid malignancies (all papillary carcinomas). The remainder had benign thyroid lesions; follicular adenomas (8), multinodular goiters (5), diffuse goiters (2) and Hashimoto thyreoiditis (1). There were no false negative or false positive cytologic diagnoses. The prevalence of thyroid malignancies among cytologic diagnoses was similar to those reported in adults. In limited number of patients with surgical follow up there were no false negative or false positive cytologic diagnoses.