title: Cytomorphological and molecular genetic findings in pediatric thyroid fine-needle aspiration.
abstract: BACKGROUND
  The Bethesda System for Reporting Thyroid Cytopathology is largely based on data from adult studies. Although thyroid nodules in children are rare, the rate of malignancy is high. The authors' aim was to analyze the cytomorphology and mutational profiles in pediatric thyroid fine-needle aspirations (FNAs).
  
  
  METHODS
  Thyroid FNAs from patients 21 years old or younger were identified from the authors' pathology archive, categorized using the Bethesda System for Reporting Thyroid Cytopathology, and correlated with histological and molecular follow-up.
  
  
  RESULTS
  A total of 179 samples from 142 patients were identified, including 96 cases (54%) with histological follow-up and 66 cases (37%) with molecular data. The diagnoses included 21 (12%) unsatisfactory, 82 (46%) negative, 43 (24%) atypia or follicular lesion of undetermined significance, 19 (11%) suspicious for follicular neoplasm, 6 (3%) suspicious for malignancy, and 8 (4%) positive for malignancy. The rate of malignancy in each category was 0%, 7%, 28%, 58%, 100%, and 100%, respectively. Of the 66 FNAs with molecular data, there were 11 (17%) positive for mutations. All mutation-positive FNAs were papillary thyroid carcinomas (PTCs) on resection. The overall sensitivity and specificity in this population were 80% and 100%, respectively.
  
  
  CONCLUSIONS
  This study demonstrates that thyroid FNA in children is a sensitive and highly specific tool. There was a 17% positivity rate for a genetic mutation, which correlated with malignancy in all cases. In comparison to adults, there was a higher prevalence of RET/PTC mutations and lower prevalence of BRAF mutations, which may in part explain the less aggressive nature of PTCs reported in children.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pennsylvania, USA. monacose@upmc.edu
authors.forename: Sara E
authors.initials: SE
authors.lastname: Monaco
authors.forename: Liron
authors.initials: L
authors.lastname: Pantanowitz
authors.forename: Walid E
authors.initials: WE
authors.lastname: Khalbuss
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Benkovich
authors.forename: John
authors.initials: J
authors.lastname: Ozolek
authors.forename: Marina N
authors.initials: MN
authors.lastname: Nikiforova
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Simons
authors.forename: Yuri E
authors.initials: YE
authors.lastname: Nikiforov
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D000293:Adolescent; D044963:Biopsy, Fine-Needle / Q000592:standards*; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D002291:Carcinoma, Papillary; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult
chemical_list: D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf