Cancer in thyroid nodules with fine-needle aspiration in Korean pediatric populations.

PURPOSE: To determine the prevalence and clinical findings of benign thyroid nodules and cancer in Korean pediatric patients with thyroid nodules. METHODS: We investigated the medical records of 134 patients aged younger than 18 years who had a goiter, thyroid nodule, thyroid mass, or thyroid cancer who underwent fine needle aspiration biopsy (FNAB). RESULTS: The study population included 113 females (84.3%) and 21 males (13.7%); the mean patient age was 16.1±2.3 years (range, 8-18 years). Of the 134 patients, 24 (18.0%) were finally diagnosed with thyroid cancer, of which 20 (83.3%) were papillary cancer and 4 (16.7%) were follicular cancer. No patient was exposed to radiation. FNAB revealed malignant cancer in 21 of the patients; 3 were initially reported as having benign tumors by FNAB, but were later diagnosed with follicular cancer. An additional 13 patients were suspected to have malignant tumors by FNAB, with a final diagnosis of nodular hyperplasia. Cystic nodules were more common in the benign group. The percentages of cervical lymphadenopathy and irregular nodular margins were higher in the malignant group compared to the benign group. Cervical lymphadenopathy and FNAB malignant findings were highly suggestive of malignant nodules. CONCLUSION: Thyroid cancer prevalence in a Korean pediatric population is comparable to reported estimates of worldwide thyroid cancer prevalence. In this population, cancer predominates on the right thyroid lobe. Papillary thyroid cancers are dominant in the Korean pediatric population but are less prevalent than in Korean adults. As expected, FNAB was highly accurate in predicting malignant nodules.