title: Phyllodes tumours of the breast - differentiating features in core needle biopsy.
abstract: OBJECTIVE
  To investigate the usefulness of histological features in the differentiation of fibroepithelial lesions of the breast (phyllodes tumours and fibroadenomas) in core needle biopsies.
  
  
  RESULTS
  Forty-nine and 69 excision-proven core biopsies of phyllodes tumours and fibroadenomas, respectively, were evaluated histologically for stromal cellular changes (overall stromal cellularity, variability in stromal cellularity, stromal cell pleomorphism, and mitotic count) and stromal architectural changes (stromal overgrowth, fragmentation of the cores, and fat in stroma). In core needle biopsies of phyllodes tumours, overall stromal cellularity, stromal cell pleomorphism and mitotic count showed good correlation with excisions. In phyllodes tumours, core needle biopsy diagnosis showed increased certainty with increasing degree of malignancy. Core biopsies of phyllodes tumours showed more consistent stromal cellular changes (overall stromal cellularity, variability in stromal cellularity, stromal pleomorphism, and mitotic count) than those of fibroadenomas. These parameters were also useful for differentiation between benign and malignant fibroepithelial lesions. For grading phyllodes tumours, stromal cell pleomorphism and mitotic activity were found to be helpful.
  
  
  CONCLUSIONS
  In the core biopsy assessment of phyllodes tumours, evaluation of selected histological parameters, particularly those pertaining to stromal cellular changes, is helpful.
authors.affiliation: Department of Pathology, Yan Chai Hospital, The Chinese University of Hong Kong, China.
authors.forename: Alex K H
authors.initials: AK
authors.lastname: Tsang
authors.forename: Siu Ki
authors.initials: SK
authors.lastname: Chan
authors.forename: Christopher C F
authors.initials: CC
authors.lastname: Lam
authors.forename: Philip C W
authors.initials: PC
authors.lastname: Lui
authors.forename: Helen H L
authors.initials: HH
authors.lastname: Chau
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
authors.forename: Gary M
authors.initials: GM
authors.lastname: Tse
mesh_terms: D000293:Adolescent; D000328:Adult; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D005260:Female; D018226:Fibroadenoma / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D003557:Phyllodes Tumor / Q000473:pathology*; D055815:Young Adult