Benign thyroid nodules in pediatric patients: determining best practices for repeat ultrasound evaluations

Background: The American Thyroid Association (ATA) recommendations for the follow-up of thyroid nodules with benign fine needle aspiration (FNA) cytology in children are largely based on adult data, despite well-characterized differences between thyroid nodules in adults and children. We aimed to determine the optimal time interval for repeat evaluation of an FNA-benign thyroid nodule in a pediatric patient. Methods: This is a retrospective chart review of patients <19 years of age from 2003 to 2013 with a benign thyroid nodule by FNA cytology. Results: We identified 43 patients with benign thyroid nodule cytology on FNA. The average age at diagnosis was 15.6 years, with female predominance (91%). Initial ultrasound (US) findings showed an average nodule size of 2.5 cm, 10% with calcifications, 37% hyperemia, 29% hypoechogenicity and 7% lymphadenopathy. Follow-up US was done in 42%. The first follow-up US occurred on average at 15 months after the initial US. Four patients had nodules with significant growth over time. One patient with papillary thyroid carcinoma (PTC) on final pathology initially had a decreasing nodule size, and then a subsequent increase in the nodule size after 4.5 years. Thyroid nodules were surgically removed in 33% with the final pathology showing a benign cytology in four patients, follicular adenoma in eight patients and PTC in two patients. Conclusions: The majority of patients with benign thyroid nodules had no significant increase in nodule size in the first year of follow-up, including one patient who was subsequently found to have PTC. We recommend follow-up US at 1 year after initial presentation in low-risk pediatric patients with benign thyroid nodule cytology.