Risk of malignancy for each Bethesda class in pediatric thyroid nodules

Abstract

PurposeThe Bethesda classification for cytology is used to classify thyroid nodules into one of six categories, and for each category there is an implied cancer risk and also recommendation for management. Despite lack of data in children, the American thyroid association promotes the use of the same management guidelines as in adults. Our aim was to study the risk of malignancy for each Bethesda class in children with thyroid nodules. MethodologyWe included all patients ≤18years of age that had underwent a thyroid fine needle aspiration (FNA) at one of two centers between January 1998 and July 2013. FNA results were reclassified according to the Bethesda criteria. Histological, repeat cytological, radiological and clinical follow-up were recorded. ResultsFifty-six patients (66 nodules) underwent FNB. Mean age was 13.6years. Numbers of nodules reported as BI-BVI were 7, 38, 11, 4, 3 and 3, respectively. Follow-up was achieved for 55 (83%) nodules. Twelve (18%) nodules were malignant by histology and revealed papillary (n=7), follicular (n=3) or insular thyroid cancer (n=2), The proportion of nodules with malignancy for BI-BVI was: 0%, 0%, 18%, 100%, 100% and 100%. ConclusionThe rate of malignancy in thyroid nodules in children seems to be higher than reported in adults. The Bethesda criteria seem to accurately identify benign nodules, but other categories have a very high rate of malignancy and BIII nodules pose a particular challenge.