title: In-situ and invasive carcinoma within a phyllodes tumor associated with lymph node metastases.
abstract: BACKGROUND
  Phyllodes tumors (cystosarcoma phyllodes) are uncommon lesions in the female breast. Rarely, the occurrence of carcinoma within a phyllodes tumor has been reported in the literature, but has never been associated with lymph node metastases.
  
  
  METHODS
  A 26-year-old woman presented with a firm, mobile, non-tender mass in the left breast and palpable lymph nodes in the left axilla. The excised lesion appeared well circumscribed and lobulated, with variable fleshy and firm areas. Microscopic examination showed a circumscribed fibroepithelial lesion with a well developed leaf-like architecture, in keeping with a benign phyllodes tumor. The epithelial component showed extensive high grade ductal carcinoma in-situ (DCIS) and invasive carcinoma of no special type, located entirely within the phyllodes tumor. Subsequent axillary lymph node dissection revealed metastatic carcinoma in four lymph nodes.
  
  
  CONCLUSIONS
  Although rare, phyllodes tumors may harbor DCIS and invasive carcinoma, with potential for lymph node metastasis.
authors.affiliation: Department of Pathology, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada. jrparfit@uwo.ca
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Parfitt
authors.forename: Chris
authors.initials: C
authors.lastname: Armstrong
authors.forename: Frances
authors.initials: F
authors.lastname: O'malley
authors.forename: Joan
authors.initials: J
authors.lastname: Ross
authors.forename: Alan B
authors.initials: AB
authors.lastname: Tuck