title: Risk factors associated with malignancy and with triage to surgery in thyroid nodules classified as Bethesda category III (AUS/FLUS).
abstract: BACKGROUND
  Selection of nodules for surgery diagnosed as Bethesda category III [atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category] is very important. We aimed at to define the predictive factors for malignancy and factors associated with triage to surgery.
  
  
  METHODS
  The records of all patients with nodules who underwent fine needle aspiration biopsy (FNAB) and classified by Bethesda reporting system as AUS/FLUS between 2011 and 2015 at our institution were reviewed. Univariate and multivariate analysis were performed to select independent factors associated with thyroid cancer and with triage to surgery. Using independent risk factors for malignancy predictive index categories were created.
  
  
  RESULTS
  Of the 485 patients who were classified as AUS/FLUS on initial FNAB, 153 underwent surgery with the associated malignancy rate of 22.8%. The malignancy rates for AUS/FLUS patients with and without repeat FNAB were 37.5% and 16.2%, respectively. Multivariate logistic regression analysis revealed that solid structure, microcalcification, hypoechogenicity, increased vascularization, and irregular margin were found to be significant and independent risk factors associated for malignancy, and solid structure, microcalcifications, increased nodule size (≥2 cm) and younger patient age (<65 years) were associated with triage to surgery.
  
  
  CONCLUSIONS
  Our findings showed that using predictive factors for malignancy in AUS/FLUS category as risk indices, an important proportion of patients (35%) who had nodules without any risk factors could be spared unnecessary surgery. We suggest that predictive indices should be considered for selection of the patients to triage to surgery.
authors.affiliation: Department of General Surgery, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: bekirkuru@gmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Kuru
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: atmaca_aysegul@yahoo.com.
authors.forename: A
authors.initials: A
authors.lastname: Atmaca
authors.affiliation: Department of General Surgery, Varto State Hospital, Varto/Mus, Turkey. Electronic address: ismailalpert@gmail.com.
authors.forename: I A
authors.initials: IA
authors.lastname: Tarim
authors.affiliation: Department of Pathology, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: mehmetkefeli@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Kefeli
authors.affiliation: Department of General Surgery, Kemerburgaz University School of Medicine, İstanbul, Turkey. Electronic address: ktopgul@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Topgul
authors.affiliation: Department of General Surgery, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: savas.yuruker@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Yoruker
authors.affiliation: Department of Radiology, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: muzafel@yahoo.com.tr.
authors.forename: M
authors.initials: M
authors.lastname: Elmali
authors.affiliation: Department of Radiology, Ondokuz Mayis University School of Medicine, Samsun, Turkey. Electronic address: danacim55@yahoo.com.
authors.forename: M
authors.initials: M
authors.lastname: Danaci
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000145:classification / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery; D016606:Thyroid Nodule / Q000145:classification / Q000473:pathology*; D013965:Thyroidectomy / Q000379:methods*; D016896:Treatment Outcome; D014218:Triage / Q000379:methods*; D057832:Watchful Waiting / Q000379:methods
keywords: Atypia of undetermined significance; Bethesda III category; Factors to triage to thyroid surgery; Predictive factors for thyroid malignancy; Selection of nodules for thyroid surgery