title: Phyllodes tumor of the breast: correlation between MR findings and histologic grade.
abstract: OBJECTIVE
  To retrospectively evaluate the magnetic resonance (MR) imaging findings of phyllodes tumor of the breast and to compare these findings with the histologic grade.
  
  
  METHODS
  Institutional review board approval and informed consent were obtained. The authors reviewed the MR findings in 30 female patients aged 16-73 years (mean, 40.2 years) with surgically confirmed phyllodes tumors. Analyzed MR findings included tumor shape, margin, internal enhancement, and size; signal intensity (SI) of tumor higher than that of normal breast tissue on T1-weighted images; SI of tumor lower than or equal to that of normal tissue on T2-weighted images; cyst wall appearance; kinetic curve assessment; and apparent diffusion coefficient (ADC). The MR findings and histologic grade were statistically analyzed to determine whether any correlations existed. Significant MR findings were compared with histopathologic findings.
  
  
  RESULTS
  Nineteen benign, six intermediate (characterized by five to nine cell reproductions at 10 high-power fields, pushing or infiltrative margins, moderate stromal cellularity, and atypia and overgrowth), and five malignant phyllodes tumors were assessed. Irregular cyst wall (P = .003), tumor SI lower than or equal to normal tissue SI on T2-weighted images (P = .005), and low ADC (P = .001) correlated significantly with histologic grade. Tumor SI higher than normal tissue SI on T1-weighted images was more frequent in the malignant (in three of five tumors) and intermediate (in three of six tumors) groups than in the benign group (in two of 19 tumors); however, it was not a significant finding (P = .024). Tumor SI higher than normal tissue SI on T1-weighted images and irregular cyst wall corresponded histopathologically to hemorrhagic infarction and necrosis, respectively. Tumor SI lower than or equal to normal tissue SI on T2-weighted images and low ADC corresponded histopathologically to stromal hypercellularity. Other findings were not significant.
  
  
  CONCLUSIONS
  Several MR findings can be used to help determine the histologic grade of phyllodes breast tumors.
authors.affiliation: Department of Clinical Radiology, Kyushu University, Japan. yabuuchi@radiol.med.kyushu-u.ac.jp
authors.forename: Hidetake
authors.initials: H
authors.lastname: Yabuuchi
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Soeda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Takashi
authors.initials: T
authors.lastname: Okafuji
authors.forename: Takashi
authors.initials: T
authors.lastname: Eguchi
authors.forename: Shuji
authors.initials: S
authors.lastname: Sakai
authors.forename: Syoji
authors.initials: S
authors.lastname: Kuroki
authors.forename: Eriko
authors.initials: E
authors.lastname: Tokunaga
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohno
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Hatakenaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D003557:Phyllodes Tumor / Q000473:pathology*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric