title: Yield of repeat fine-needle aspiration biopsy and rate of malignancy in patients with atypia or follicular lesion of undetermined significance: the impact of the Bethesda System for Reporting Thyroid Cytopathology.
abstract: BACKGROUND
  Atypia/follicular lesion of undetermined significance (A/FLUS) is a new category in the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) for which repeat fine-needle aspiration biopsy (FNAB) is recommended.
  
  
  METHODS
  A retrospective review was completed to evaluate the impact of the BSRTC on management of nodular thyroid disease. Patients were divided into pre-BSRTC and BSRTC groups. A comparative analysis of cytopathologic diagnoses and rates of repeat FNAB and malignancy was completed.
  
  
  RESULTS
  FNAB was performed in 730 patients: 337 pre-BSRTC and 393 BSRTC. There was a decrease in follicular/Hürthle cell neoplasm (FN/HCN; 9.5% vs 3.6%, P = .001) but no difference in the rate of malignancy (6.5% vs 6.4%, P = 1.0). Fewer operations (29% vs 21%, P = .02) and more repeat FNABs (3.9% vs 11%, P < .001) were performed in the BSRTC group. Sixty-one (16%) patients had A/FLUS, 56 with complete follow-up. Repeat FNAB in 26 patients was benign (11), A/FLUS (6), suspicious for malignancy (4), FN/HCN (2), and nondiagnostic (3). Thirty-two (57%) patients underwent thyroidectomy, and 6 patients (19%) were diagnosed with cancer.
  
  
  CONCLUSIONS
  The BSRTC resulted in more frequent repeat FNAB, fewer thyroidectomies and no change in malignancy rate. In patients with A/FLUS, repeat FNAB was definitive in 65% with a rate of malignancy of 19%.
authors.affiliation: Department of Surgery, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH 44109-1998, USA.
authors.forename: Joy C
authors.initials: JC
authors.lastname: Chen
authors.forename: S Carter
authors.initials: SC
authors.lastname: Pace
authors.forename: Boris A
authors.initials: BA
authors.lastname: Chen
authors.forename: Amer
authors.initials: A
authors.lastname: Khiyami
authors.forename: Christopher R
authors.initials: CR
authors.lastname: McHenry
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000473:pathology; D018249:Adenoma, Oxyphilic / Q000175:diagnosis / Q000473:pathology; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D016606:Thyroid Nodule / Q000145:classification / Q000175:diagnosis / Q000473:pathology*