title: Hürthle cell metaplasia on fine-needle aspiration biopsy is not by itself an indication for thyroid surgery.
abstract: BACKGROUND
  The aim of this study was to assess the malignancy rate in patients with Hürthle cell metaplasia (HCM) on fine-needle aspiration biopsy (FNAB).
  
  
  METHODS
  The pathology results of patients with benign colloid (BC) and HCM on FNAB were compared using a prospective database.
  
  
  RESULTS
  One hundred fifty-three (65%) patients had BC on FNAB, and 82 (35%) had HCM. The mean nodule size was similar in both groups (25 ± 2 mm vs 26 mm ± 2 mm, P = .83). Malignancy was identified on the final pathology report in 21 (14%) versus 13 (16%) patients in the BC and HCM groups, respectively (P = .66). Of the patients with malignancy, the tumor was determined as microcarcinoma in 76% in the BC groups versus 85% in the HCM group (P = .48) and as incidental in 71% versus 85% (P = .39).
  
  
  CONCLUSIONS
  A result of HCM on FNAB carries a similar rate of malignancy as BC and should not be treated differently. Most of the malignancies found were incidental microcarcinomas.
authors.affiliation: Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, WI 53792, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Hudak
authors.forename: Haggi
authors.initials: H
authors.lastname: Mazeh
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Sippel
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
mesh_terms: D018249:Adenoma, Oxyphilic; D044963:Biopsy, Fine-Needle; D056364:Colloid Cysts / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D024862:Oxyphil Cells / Q000473:pathology*; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000473:pathology* / Q000601:surgery; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy