title: Metaplastic carcinoma of the breast: mammographic and sonographic findings.
abstract: OBJECTIVE
  We investigated the mammographic, sonographic, and pathologic findings in metaplastic carcinoma of the breast.
  
  
  METHODS
  The mammographic (n = 16) and sonographic (n = 11) findings in 16 patients with metaplastic carcinoma of the breast were analyzed retrospectively along with pathologic findings. Whenever possible, results of preoperative fine-needle aspiration biopsy and immunohistochemical studies were obtained.
  
  
  RESULTS
  All patients presented with a palpable breast mass. The mean size of the lesions at pathologic examination was 4.2 cm. On mammography, 15 patients had a mass (1 patient had 2 masses), and 1 patient had only clustered microcalcifications without an associated mass. The mean longest diameter of the 16 masses on mammography was 4.6 cm. Eleven lesions (69%) were round to ovoid in shape, 13 lesions (81%) showed ill-defined or obscured margins, and 10 lesions (63%) showed associated architectural distortion. On sonography, 6 (55%) of 11 lesions were round to ovoid, 9 lesions (82%) had well-defined margins, and 6 lesions (55%) showed complex echogenicity with solid and cystic components. At pathologic examination, 4 of these 6 lesions showed hemorrhagic or cystic necrosis. Axillary lymph nodes were positive in 6 (40%) of 15 patients in whom axillary node dissection was performed.
  
  
  CONCLUSIONS
  Metaplastic carcinoma of the breast manifests as a rapidly growing, mammographically ill-defined round mass with associated architectural distortion on mammograms. Complex echogenicity with solid and cystic components may be seen sonographically and is related to hemorrhagic or cystic necrosis seen pathologically.
authors.affiliation: Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poong Nap-Dong, Song Pa-Ku, Seoul 138-736, South Korea.
authors.forename: J M
authors.initials: JM
authors.lastname: Park
authors.forename: B K
authors.initials: BK
authors.lastname: Han
authors.forename: W K
authors.initials: WK
authors.lastname: Moon
authors.forename: Y H
authors.initials: YH
authors.lastname: Choe
authors.forename: S H
authors.initials: SH
authors.lastname: Ahn
authors.forename: G
authors.initials: G
authors.lastname: Gong
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008327:Mammography; D008679:Metaplasia; D008875:Middle Aged; D012189:Retrospective Studies; D012509:Sarcoma / Q000175:diagnosis*; D016217:Ultrasonography, Mammary
chemical_list: D014408:Biomarkers, Tumor