title: Ultrasonographic characteristics of mammographically occult small breast cancer.
abstract: OBJECTIVE
  To analyze significant ultrasonographic findings of small malignant breast mass (≤10 mm) which were occult on mammography.
  
  
  METHODS
  The study included 190 small breast masses (≤10 mm), demonstrated on breast ultrasonography, but not mammography. Histopathology (when the masses were biopsied) or serial breast ultrasonography (for at least 24 months) were used to confirm benign or malignant condition of the masses. Univariate and multivariate logistic regression analysis were used to identify significant characteristic malignant findings on ultrasonography.
  
  
  RESULTS
  Of 190 masses, 46 were cancer, and 144 were benign. On multivariate analyses, irregular shape (odds ratio [OR], 10.4) and not circumscribed margin (OR, 31.6) were significant features to differentiate between benign and malignant breast masses. However, low width/anteroposterior ratio, echogenic halo, hypoechogenecity and posterior acoustic shadow, which were predictors for malignancy in large breast mass, were not documented in small mass.
  
  
  CONCLUSIONS
  In conclusion, irregular shape and not circumscribed margin detected during ultrasonography were strong predictive signs of malignancy for small malignant breast mass.
authors.affiliation: Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Pornpim
authors.initials: P
authors.lastname: Korpraphong
authors.forename: Oranan
authors.initials: O
authors.lastname: Tritanon
authors.forename: Woranuj
authors.initials: W
authors.lastname: Tangcharoensathien
authors.forename: Tamnit
authors.initials: T
authors.lastname: Angsusinha
authors.forename: Suebwong
authors.initials: S
authors.lastname: Chuthapisith
keywords: Breast; Carcinoma; Ultrasonography