title: The potential diagnostic role of the number of ultrasonographic characteristics for patients with thyroid nodules evaluated as bethesda I-v.
abstract: OBJECTIVE
  Fine-needle aspiration cytology (FNAC) is considered to be the most reliable method of examination for thyroid nodules. However, when thyroid nodules are evaluated as Bethesda I-V, the role of ultrasonography is considered to be enhanced. We investigated the association between a number of ultrasonographic (US) characteristics and the risk of thyroid malignancy, and assessed the optimal compromise on the number of US characteristics for predicting thyroid malignancy.
  
  
  METHODS
  Seventy-three patients, whose thyroid nodules were evaluated as Bethesda I-V by FNAC prior to surgery, were treated surgically. A number of US characteristics, such as microcalcification, irregular margins, hypoechogenicity, a taller-than-wide shape, and the absence of halo sign, were assessed before surgery. The optimal compromise on the number of US characteristics was analyzed using a receiver operating characteristics (ROC) curve. The area under the ROC curve (AUC) represents the overall discriminatory ability of a test.
  
  
  RESULTS
  The risk of malignancy was 11.8% in patients without any US characteristics, 44.4% in those with one characteristic, 61.5% in those with two characteristics, 75% in those with three characteristics, 90% in those with four characteristics, and 100% in those with five characteristics. The AUC was favorable (0.81599). At least two US characteristics were revealed to be the optimal compromise on the number of US characteristics based on the ROC curve.
  
  
  CONCLUSIONS
  We proved the role of the number of US characteristics in predicting thyroid malignancy. It was thought that a surgical approach should be considered for patients with at least two US characteristics.
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sakashita
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Homma
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Hatakeyama
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Mizumachi
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kano
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Furusawa
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iizuka
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Hoshino
authors.affiliation: Surgical Pathology, Hokkaido University Hospital , Sapporo , Japan.
authors.forename: Kanako C
authors.initials: KC
authors.lastname: Hatanaka
authors.affiliation: Translational Research and Clinical Trial Center, Hokkaido University Hospital , Sapporo , Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Oba
authors.affiliation: Otolaryngology - Head and Neck Surgery, Hokkaido University Graduate School of Medicine , Sapporo , Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukuda
keywords: ROC curve; fine-needle aspiration cytology; thyroid cancer; thyroidectomy; ultrasound image