title: Rate of malignancy in MRI-detected probably benign (BI-RADS 3) lesions.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the malignancy rate in MRI-detected probably benign (BI-RADS 3) lesions in women without a history of breast cancer.
  
  
  METHODS
  In this study, 1265 patients underwent breast MRI during a 7-year period. One hundred and eight (8.5%) patients with a nonpalpable breast lesion classified as BI-RADS 3 at MRI and with a needle biopsy or adequate follow-up of at least 24 months were included. Statistical analysis included calculation of the negative predictive value with its 95% CI.
  
  
  RESULTS
  Of 108 lesions, 107 (99.1%) were correctly assessed as probably benign, resulting in a negative predictive value of 99.1% (95% CI, 94.99-99.98%). Histopathology was requested by the patient or referring physician in 44 patients. Of these, 43 (39.8%) lesions were classified as benign and one (0.9%) as malignant. There were no changes evident in any of the remaining 64 (59.2%) lesions during follow-up (range, 2-9 years).
  
  
  CONCLUSIONS
  In MRI-detected probably benign (BI-RADS 3) lesions, the malignancy rate is low and within the accepted cancer rate for mammographically or sonographically detected BI-RADS 3 lesions. Short-term follow-up MRI at intervals of 6, 12, and 24 months in MRI BI-RADS 3 lesions remains a strong tool with which to detect suspicious lesions. Interval changes in size, morphology, or enhancement are regarded as indicative of malignancy.
authors.affiliation: 1 Diagnostikum Graz-Süd West, Weblinger Guertel 25, 8054 Graz, Austria.
authors.forename: Claudio
authors.initials: C
authors.lastname: Spick
authors.forename: Dieter H M
authors.initials: DH
authors.lastname: Szolar
authors.forename: Pascal A
authors.initials: PA
authors.lastname: Baltzer
authors.forename: Manfred
authors.initials: M
authors.lastname: Tillich
authors.forename: Pia
authors.initials: P
authors.lastname: Reittner
authors.forename: Klaus W
authors.initials: KW
authors.lastname: Preidler
authors.forename: Katja
authors.initials: K
authors.lastname: Pinker-Domenig
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Helbich
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001317:Austria / Q000453:epidemiology; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D055088:Early Detection of Cancer / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D055815:Young Adult