title: Imaging differences in metaplastic and invasive ductal carcinomas of the breast.
abstract: OBJECTIVE
  The purpose of this study was to compare the imaging features of metaplastic breast carcinoma with those of invasive ductal carcinoma.
  
  
  METHODS
  Women diagnosed on preoperative mammography or sonography with metaplastic breast carcinoma and T-stage matched invasive ductal carcinoma of the breast from a single pathology database were included in the study. Clinical and pathologic information on all metaplastic cancers was documented. Mammography and sonography variables were recorded using the BI-RADS lexicon. Groups were compared using Fisher's exact test, the chi-square test, or Wilcoxon's rank sum test, as appropriate.
  
  
  RESULTS
  Forty-three patients diagnosed with metaplastic carcinoma were matched to 43 patients with ductal carcinoma by tumor T stage. Patients with metaplastic carcinoma were younger (median, 46 vs 53 years, p = 0.048) than those with ductal carcinoma. Mammographically, metaplastic carcinomas were less frequently irregular in shape (16% vs 74%, p < 0.0001) and less frequently showed microlobulated or spiculated margins (19% vs 56%, p = 0.0008) and calcifications (25% vs 51%, p = 0.02) when compared with ductal carcinomas. Sonographically, metaplastic carcinomas were less frequently irregular in shape (27% vs 69%, p = 0.001) and less frequently showed angular margins (9% vs 49%) and posterior acoustic shadowing (9% vs 49%, p < 0.0001).
  
  
  CONCLUSIONS
  Characteristic malignant imaging features, including irregular shape, spiculated margins, segmentally distributed pleomorphic calcifications, and posterior acoustic shadowing, are uncommon in metaplastic carcinomas. These carcinomas tend to show more benign imaging features, such as round or oval shape with circumscribed margins, when compared with ductal carcinomas.
authors.affiliation: Department of Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, PO Box 301439, Unit 1350, Houston, TX 77230, USA. wyang@di.mdacc.tmc.edu
authors.forename: Wei Tse
authors.initials: WT
authors.lastname: Yang
authors.forename: Bryan
authors.initials: B
authors.lastname: Hennessy
authors.forename: Kristine
authors.initials: K
authors.lastname: Broglio
authors.forename: Chadwick
authors.initials: C
authors.lastname: Mills
authors.forename: Nour
authors.initials: N
authors.lastname: Sneige
authors.forename: W Grant
authors.initials: WG
authors.lastname: Davis
authors.forename: Vicente
authors.initials: V
authors.lastname: Valero
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Hunt
authors.forename: Michael Z
authors.initials: MZ
authors.lastname: Gilcrease
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008679:Metaplasia / Q000000981:diagnostic imaging; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods