title: Metastases to the breast from extramammary malignancies−sonographic features.
abstract: OBJECTIVE
  To evaluate the clinical and sonographic (US) features of metastatic tumors from extramammary malignancies to the breast.
  
  
  METHODS
  This study included 23 patients with pathologically proven metastases in the breast. Two radiologists retrospectively analyzed the images from US (n = 23), mammography (n = 11), and MRI (n = 5) examinations according to BIRADS.
  
  
  RESULTS
  Patients presented with a palpable mass or diffuse breast swelling (21/23) or were asymptomatic (2/23). Eighteen patients had solitary or multiple breast masses on US. The common US finding was an ovoid hypoechoic mass with a noncircumscribed margin. The final assessment categories were BIRADS 3 (probably benign finding) in 6 cases (25%) and BIRADS 4 (suspicious abnormality) in 18 cases (75%). In five patients, US displayed a diffuse infiltrative pattern without a focal lesion, which was categorized as BIRADS 4.
  
  
  CONCLUSIONS
  Metastatic tumors in the breast have a wide range of sonographic appearances, with some resembling benign lesions. Any newly developed mass in a patient with a known history of extramammary malignancy, even with a probably benign US appearance, should undergo biopsy for pathologic confirmation.
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-Gu, Seoul 137-701, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Lee
authors.forename: Sung Hun
authors.initials: SH
authors.lastname: Kim
authors.forename: Bong Joo
authors.initials: BJ
authors.lastname: Kang
authors.forename: Eun Suk
authors.initials: ES
authors.lastname: Cha
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Kim
authors.forename: Jae Jeong
authors.initials: JJ
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014463:Ultrasonography