title: Breast MR imaging in patients with axillary node metastases and unknown primary malignancy.
abstract: OBJECTIVE
  To assess the usefulness of magnetic resonance (MR) imaging of the breast in patients with malignant axillary adenopathy and unknown primary malignancy.
  
  
  METHODS
  Between October 1993 and December 1997, 38 women with malignant axillary adenopathy and negative mammographic and physical examination findings underwent contrast material-enhanced MR imaging. Sixteen patients were excluded due to axillary tail cancer (n = 7), lack of follow-up (n = 4), second primary malignancy (n = 3), or chemotherapy before MR imaging (n = 2). The study population comprised the remaining 22 patients. Histopathologic findings were available in 20 patients; follow-up MR imaging findings were available in two patients.
  
  
  RESULTS
  MR imaging depicted a primary breast cancer in 19 patients (86%; identified at excisional biopsy or mastectomy in 17, resolved on follow-up MR images during treatment in two). MR imaging depicted 4-30-mm cancers (mean, 17 mm), which correlated closely with histopathologic size. Two patients (9%) had false-negative findings: (a) One had a 2-mm invasive ductal carcinoma, and (b) one had 17- and 20-mm invasive ductal carcinomas. Of the 19 patients, 11 underwent mastectomy, seven underwent breast-conservation therapy, and one did not undergo a surgical procedure.
  
  
  CONCLUSIONS
  MR imaging is very sensitive for the detection of mammographically and clinically occult breast cancer in patients with malignant axillary adenopathy. In these patients, MR imaging offers potential not only for cancer detection but also for staging the cancer within the breast, which may be useful for treatment planning.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical Center, Philadelphia 19104, USA. orel@oasis.rad.upenn.edu
authors.forename: S G
authors.initials: SG
authors.lastname: Orel
authors.forename: S P
authors.initials: SP
authors.lastname: Weinstein
authors.forename: M D
authors.initials: MD
authors.lastname: Schnall
authors.forename: C A
authors.initials: CA
authors.lastname: Reynolds
authors.forename: L M
authors.initials: LM
authors.lastname: Schuchter
authors.forename: D L
authors.initials: DL
authors.lastname: Fraker
authors.forename: L J
authors.initials: LJ
authors.lastname: Solin
mesh_terms: D001365:Axilla; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000556:secondary*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA