title: Older age and larger tumor size predict malignancy in hürthle cell neoplasms of the thyroid.
abstract: BACKGROUND
  Hürthle cell neoplasms (HCNs) are rare tumors of the thyroid gland. The definitive treatment for Hürthle cell carcinoma (HCC) is total thyroidectomy, while thyroid lobectomy is adequate for Hürthle cell adenoma (HCA). However, differentiating HCC from HCA either before or during surgery is a challenge. The purpose of this study was to identify factors that predict malignancy in patients with HCN.
  
  
  METHODS
  Between May 1994 and January 2007, 1,199 patients underwent thyroid surgery at an academic medical center. Medical records of 55 consecutive patients who underwent thyroid resections for the preoperative diagnosis of HCN were reviewed.
  
  
  RESULTS
  Of the 55 patients with HCN, 46 (84%) had adenomas and 9 (16%) had carcinomas. Patients with HCC were significantly older than those with HCA (66 +/- 6 years versus 53 +/- 2 years, P = 0.01). Patients with carcinoma also had significantly larger thyroid nodules (4.5 +/- 0.7 cm versus 2.5 +/- 0.2 cm, P < 0.001). All HCNs less than 2 cm in diameter were benign. The malignancy rate increased with nodule size: 18% of nodules measuring 2-4 cm, and 44% of those larger than 4 cm were HCC. One patient with HCC had recurrence of the disease, but there were no disease-related deaths.
  
  
  CONCLUSIONS
  Advanced patient age and larger nodule size are two important factors that predict malignancy in patients with HCN. In patients with these and other known risk factors for HCC, total thyroidectomy should be considered.
authors.affiliation: Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, H4/750 Clinical Science Center, 600 Highland Avenue, Madison, WI, 53792, USA.
authors.forename: Yi Wei
authors.initials: YW
authors.lastname: Zhang
authors.forename: David Yu
authors.initials: DY
authors.lastname: Greenblatt
authors.forename: Daniel
authors.initials: D
authors.lastname: Repplinger
authors.forename: Anna
authors.initials: A
authors.lastname: Bargren
authors.forename: Joel T
authors.initials: JT
authors.lastname: Adler
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Sippel
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D018249:Adenoma, Oxyphilic / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome