title: Underestimation of DCIS at MRI-guided vacuum-assisted breast biopsy.
abstract: OBJECTIVE
  The study objective was to assess the rate of underestimation of ductal carcinoma in situ (DCIS) at MRI-guided 9-gauge vacuum-assisted breast biopsy.
  
  
  METHODS
  An institutional review board-approved retrospective review was performed of 373 consecutive lesions that had undergone MRI vacuum-assisted breast biopsy. In 34 lesions with subsequent surgery, vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion. DCIS underestimates were lesions for which vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion at biopsy and surgery yielded invasive cancer. Records and pathology findings were reviewed.
  
  
  RESULTS
  Among 34 lesions, vacuum-assisted breast biopsy histology was DCIS in 29 and DCIS with possible microinvasion in five. Of 29 lesions yielding DCIS at MRI vacuum-assisted breast biopsy, surgical excision revealed invasive cancer in five (17%; 95% CI, 6-36%). The DCIS underestimation rate was significantly higher in lesions 6 cm or larger versus smaller lesions (60% vs 8%, p = 0.02). MRI lesion type, kinetics, number of specimens, menopausal status, and target sampling versus excision did not significantly affect underestimation. Of five lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy, surgery revealed invasive carcinoma in four (80%; 95% CI, 28-99%). DCIS underestimation was significantly more likely if MRI vacuum-assisted breast biopsy showed possible microinvasion than if it did not (80% vs 17%, p =0.01).
  
  
  CONCLUSIONS
  Underestimation occurred in 17% of lesions yielding DCIS and in 80% of lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy. DCIS underestimation was significantly more likely in lesions measuring 6 cm or larger. No other patient or lesion factors significantly affected DCIS underestimation at MRI vacuum-assisted breast biopsy.
authors.affiliation: Breast Imaging Section, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10021, USA.
authors.forename: Jung-min
authors.initials: JM
authors.lastname: Lee
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Kaplan
authors.forename: Melissa P
authors.initials: MP
authors.lastname: Murray
authors.forename: Marzena
authors.initials: M
authors.lastname: Mazur-Grbec
authors.forename: Tade
authors.initials: T
authors.lastname: Tadic
authors.forename: Damir
authors.initials: D
authors.lastname: Stimac
authors.forename: Laura
authors.initials: L
authors.lastname: Liberman
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000295:instrumentation*; D001943:Breast Neoplasms / Q000473:pathology*; D002278:Carcinoma in Situ / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D016009:Chi-Square Distribution; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional; D008875:Middle Aged; D012189:Retrospective Studies; D014618:Vacuum