Risk of malignancy for each Bethesda class in pediatric thyroid nodules Olov Norlén a, b, ⁎, Amanda Charlton c , Leba M. Sarkis e , Tony Henwood c , Albert Shun d , Anthony J. Gill e , Leigh Delbridge a a University of Sydney Endocrine Surgery Unit, Royal North Shore Hospital, Australia b Department of Surgical Sciences, Uppsala University, Sweden c Department of Histopathology, Children's Westmead Hospital, Australia d Department of Surgery, Children's Westmead Hospital, Australia e Department of Anatomical Pathology, Royal North Shore Hospital and University of Sydney, Australia abstract article info Article history: Received 4 July 2014 Received in revised form 1 October 2014 Accepted 14 October 2014 Available online xxxx Key words: Thyroid Nodule Fine needle biopsy Pediatric Bethesda Purpose: The 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. Methodology: We included all patients ≤18 years 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. Results: Fifty-six patients (66 nodules) underwent FNB. Mean age was 13.6 years. 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%. Conclusion: The 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 malig- nancy and BIII nodules pose a particular challenge. © 2014 Elsevier Inc. All rights reserved. The incidence of palpable thyroid nodules varies between 2 and 65 per cent in different populations, and the large variation is depen- dent on screening method used, age of the population and iodine suffi- ciency status. The highest prevalence rates are seen in studies of histopathological examination postmortem, followed by thyroid ultra- sound and palpation. In children the prevalence of thyroid nodules is much lower, around 0.2–5 per cent when ultrasound is used [1,2]. However, the relative proportion of malignant versus benign thyroid nodules in children is reported to be higher than in adults in numerous reports, 9–50 per cent versus 5–14 per cent respectively [1–3]. The cornerstones of work-up for pediatric thyroid nodules include clinical history, physical examination, and thyroid function tests includ- ing calcitonin, thyroid ultrasound, and cytology by fine needle aspira- tion [1,3]. The sensitivity, specificity and accuracy to predict thyroid malignancy by FNA in children ranges from 69–96 per cent, 66–100 per cent and 75–95 per cent respectively [1,3–5]. In adults, the Bethesda criteria for reporting of thyroid nodule cytology are widely used [6]. The Bethesda criteria comprise six classes, where each class has an implied cancer risk and also an associated recommendation for management according to the American Thyroid Association (ATA) (Table 1) [6,7]. Around 20 per cent of all thyroid nodules in adults are Bethesda class III or IV [7]. These nodules are a diagnostic dilemma, since only approximately 20 per cent turn out to be malignant in adults [8]. Although the malignancy risk for each Bethesda class is not well studied in children, the American Thyroid Association guidelines pro- mote the same management for each Bethesda class for children and adults [7]. These guidelines may be misleading, as the implied cancer risk for each Bethesda category is most likely different in pediatric thyroid nodules. In fact, a recently published study showed that 28 per cent of Bethesda III nodules and 58 per cent of Bethesda IV nodules in children were malignant [9]. The aim with this study was to investigate the malignancy risk for each Bethesda class in a relatively large cohort of pediatric thyroid nodules to see if the adult management guidelines for the Bethesda criteria are reasonable to practice also in children. 1. Patients and methods 1.1. Patients We included all patients less than 18 years of age who underwent fine needle aspiration of thyroid nodules at the surgical pathology department, Royal North Shore Hospital, or the pathology department Journal of Pediatric Surgery xxx (2014) xxx–xxx ⁎ Corresponding author at: University of Sydney Endocrine Surgical Unit, Endocrine Surgical Office, Level 3, Acute Services Building, St Leonards 2065, NSW, Australia. Tel.: +61 9437 1731; fax: +61 94371732. http://dx.doi.org/10.1016/j.jpedsurg.2014.10.046 0022-3468/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg Please cite this article as: Norlén O, et al, Risk of malignancy for each Bethesda class in pediatric thyroid nodules, J Pediatr Surg (2014), http://dx. doi.org/10.1016/j.jpedsurg.2014.10.046