title: Histologic work-up of non-palpable breast lesions classified as probably benign at initial mammography and/or ultrasound (BI-RADS category 3).
abstract: OBJECTIVE
  To determine the accuracy of a probably benign assessment of non-palpable breast lesions (BI-RADS category 3) at mammography and/or ultrasound with immediate histological work-up.
  
  
  METHODS
  Stereotactic or ultrasound guided core needle breast biopsy (NBB) was performed to evaluate 288 lesions, which were prospectively assessed as BI-RADS category 3. Imaging findings included 195 masses, 73 calcification cases, 16 focal asymmetries, and four architectural distortion cases. After NBB, patients underwent either open surgical biopsy (OSB) (n=204) or mammographic follow-up (n=84) for at least 24 months. Histological results of NBB were compared with those of OSB.
  
  
  RESULTS
  Three of the 288 lesions (1.0%) proved to be malignant at histological work-up, two of them were ductal carcinoma in situ (DCIS) and one of them was an invasive carcinoma. NBB revealed invasive carcinoma in 1/288 (0.35%) and atypical ductal hyperplasia (ADH) in 13/288 (4.5%) lesions. OSB revealed DCIS in 2/204 (1%) and invasive carcinoma in 1/204 (0.5%) lesions. The two DCIS were underestimated as ADH by NBB. The remaining 285 (99%) lesions proved to be benign at OSB or remained stable during follow-up.
  
  
  CONCLUSIONS
  Confirmed by tissue diagnosis, the low likelihood of malignancy of prospectively assessed probably benign lesions is below the 2% threshold established for BI-RADS category 3. Imaging follow-up is a safe and effective alternative to immediate histological work-up for such lesions.
authors.affiliation: Medical University of Vienna, Department of Radiology, Division of Molecular and Gender Imaging, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Gruber
authors.forename: S
authors.initials: S
authors.lastname: Jaromi
authors.forename: M
authors.initials: M
authors.lastname: Rudas
authors.forename: G
authors.initials: G
authors.lastname: Pfarl
authors.forename: C C
authors.initials: CC
authors.lastname: Riedl
authors.forename: D
authors.initials: D
authors.lastname: Flöry
authors.forename: O
authors.initials: O
authors.lastname: Graf
authors.forename: E A
authors.initials: EA
authors.lastname: Sickles
authors.forename: T H
authors.initials: TH
authors.lastname: Helbich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001317:Austria / Q000453:epidemiology; D001707:Biopsy, Needle / Q000706:statistics & numerical data*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008327:Mammography / Q000706:statistics & numerical data*; D008875:Middle Aged; D010173:Palpation / Q000706:statistics & numerical data; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult