title: Should atypia of undetermined significance be subclassified to better estimate risk of thyroid cancer?
abstract: BACKGROUND
  Atypia or follicular lesion of undetermined significance (AUS) is a cytologic category of thyroid aspirates with a wide range of reported malignancy. We aimed to determine whether specific cytologic features are associated with different rates of thyroid malignancy.
  
  
  METHODS
  All thyroid fine needle aspiration biopsies with AUS from 2010 to 2012 were reanalyzed. Cytologic features were correlated with final pathology. Cytopathologists were blinded to the original cytologic interpretation and final diagnosis.
  
  
  RESULTS
  Seventy-six patients had AUS; 39 (54%) underwent surgery with a malignancy rate of 18%. Specimens with moderate or large amount of thin colloid and absent or few nuclear inclusions had a >88% rate of benign disease. More than rare nuclear inclusions or grooves were associated with a higher rate of cancer (75% vs 9%, P = .005; 45% vs 7%, P = .003).
  
  
  CONCLUSIONS
  Patients with AUS and more than rare nuclear inclusions or grooves are at higher risk for cancer and should forego repeat fine needle aspiration biopsy and undergo thyroidectomy.
authors.affiliation: Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Joy C
authors.initials: JC
authors.lastname: Chen
authors.affiliation: Department of Pathology, Lake Health, Willoughby, OH, USA.
authors.forename: S Carter
authors.initials: SC
authors.lastname: Pace
authors.affiliation: Department of Pathology, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
authors.forename: Amer
authors.initials: A
authors.lastname: Khiyami
authors.affiliation: Department of Surgery, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA. Electronic address: cmchenry@metrohealth.org.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: McHenry
mesh_terms: D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000473:pathology* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy
keywords: Atypia; Cytology; Thyroid cancer; Thyroid nodule