title: Galactoceles mimicking suspicious solid masses on sonography.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the sonographic appearance of a galactocele that can sonographically mimic a suspicious solid mass and to differentiate between a galactocele and a solid mass.
  
  
  METHODS
  From September 2002 to February 2004, 33 galactoceles classified as Breast Imaging Reporting and Data System category 4 were included. They were all confirmed by sonographically guided core biopsies. Their sonographic imaging and clinical findings were reviewed retrospectively.
  
  
  RESULTS
  The lesions had a round or irregular shape in 26 patients (78.8%), a noncircumscribed margin in 31 (93.9%), a nonparallel orientation in 22 (66%), and posterior shadowing in 13 (39.4%). Twenty-five nodules (75.8%) had internal hypoechogenicity or mixed echogenicity. Twenty-nine (87.9%) of 33 lesions showed a relatively sharp convex echogenic rim on the anterior or posterior wall.
  
  
  CONCLUSIONS
  Galactoceles have various sonographic findings, many of which are similar to those of suspicious solid breast masses. However, there is a tendency for a galactocele to appear as a small, round hypoechoic nodule with an indistinct or microlobulated margin and mild posterior shadowing. It is helpful to search for a partial anterior or posterior echogenic rim to identify a galactocele.
authors.affiliation: Department of Diagnostic Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea. ekkim@yumc.yonsei.ac.kr
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Kim
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Park
authors.forename: Hae Kyoung
authors.initials: HK
authors.lastname: Jung
authors.forename: Ki Keun
authors.initials: KK
authors.lastname: Oh
authors.forename: Jae Yeon
authors.initials: JY
authors.lastname: Seok
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods; D001941:Breast Diseases / Q000000981:diagnostic imaging*; D003560:Cysts / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional; D016217:Ultrasonography, Mammary