title: Frequency, upgrade rates, and characteristics of high-risk lesions initially identified with breast MRI.
abstract: OBJECTIVE
  The purpose of this article is to determine the frequency, outcomes, and imaging features of high-risk lesions initially detected by breast MRI, including atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar.
  
  
  METHODS
  A retrospective review of our MRI pathology database was performed to identify all lesions initially detected with MRI (January 2003 through May 2007) that underwent imaging-guided needle biopsy yielding high-risk histopathologic abnormalities. Patient age, clinical indication, MRI BI-RADS lesion features, biopsy method, and histopathologic diagnosis were recorded. The frequencies of high-risk findings at needle biopsy and rates of upgrade to malignancy at surgical excision were compared across lesion imaging features with Fisher's exact test.
  
  
  RESULTS
  Four hundred eighty-two MRI-detected suspicious lesions underwent needle biopsy. High-risk histopathologic abnormalities were present in 61 (12.7%) of 482 lesions: 51 (10.6%) atypical ductal hyperplasias, six (1.2%) atypical lobular hyperplasias, three (0.6%) lobular carcinomas in situ, and one (0.2%) radial scar. Correlation between the lesion site and pathology at surgical excision was confirmed for 39 of 61 lesions. Twelve (30.8%) of those 39 lesions were upgraded to malignancy (11 atypical ductal hyperplasias and one atypical lobular hyperplasia); five (41.7%) of the 12 malignancies were invasive cancer, and seven (58.3%) were ductal carcinomas in situ. No significant lesion features predictive of subsequent upgrade to malignancy were discovered.
  
  
  CONCLUSIONS
  There are no specific imaging features that predict upgrade for high-risk lesions when detected with MRI. Therefore, surgical excision is recommended because upgrade to invasive carcinoma or ductal carcinoma in situ can occur in up to 31% of cases, regardless of biopsy technique.
authors: Department of Radiology, University of Washington Medical Center, Seattle, WA, USA.
authors: Roberta M
authors: RM
authors: Strigel
authors: Peter R
authors: PR
authors: Eby
authors: Wendy B
authors: WB
authors: Demartini
authors: Robert L
authors: RL
authors: Gutierrez
authors: Kimberly H
authors: KH
authors: Allison
authors: Sue
authors: S
authors: Peacock
authors: Constance D
authors: CD
authors: Lehman
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D001941:Breast Diseases / Q000175:diagnosis* / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000473:pathology; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA