title: Predictors of phyllodes tumours on core biopsy specimens of fibroepithelial neoplasms.
abstract: OBJECTIVE
  To establish histological and biological parameters that can predict phyllodes tumours on core biopsy specimens of indeterminate fibroepithelial neoplasms.
  
  
  RESULTS
  Core biopsy specimens of fibroepithelial lesions diagnosed at the Department of Pathology, Singapore General Hospital from 2002 to 2007 were reviewed. Cases in which phyllodes tumour was favoured, or could not be ruled out, were evaluated for stromal cellularity/distribution, nuclear atypia and mitoses, stromal overgrowth, epithelial fronding, epithelial hyperplasia, configuration of lesional edge, presence of pseudoangiomatous stromal hyperplasia and of adipose tissue. Antibodies to Ki67, topoisomerase IIalpha, CD34, CD117 and Bcl-2 were applied to sections subjected to immunohistochemistry using the streptavidin-biotin method. Findings were correlated with subsequent excisions. Of 261 core biopsy specimens of fibroepithelial lesions, 98 (37%) comprised cases in which phyllodes tumour could not be excluded and 57 (58%) had subsequent open surgical excisions. Marked stromal hypercellularity (5/5; 100%) and nuclear atypia (1/1; 100%), stromal overgrowth (17/17; 100%), mitoses > or =2/10 high-power fields (18/18; 100%) and ill-defined lesional borders (16/16 phyllodes tumours; 100%) were features in core biopsy specimens that exclusively predicted phyllodes tumour on excision. Moderate stromal hypercellularity (20/27 phyllodes tumours; 74%), stromal overgrowth, moderate nuclear atypia (14/16 phyllodes tumours; 87%), pseudoangiomatous stromal hyperplasia (19/23 phyllodes tumours; 83%) significantly correlated with their subsequent excisions. Immunohistochemical markers Ki67 > or =5% and topoisomerase IIalpha> or =5%, and reduced or patchy CD34 on core biopsy specimens correlated significantly with a diagnosis of phyllodes.
  
  
  CONCLUSIONS
  Stromal hypercellularity, combined with key histological features and immunohistochemical markers Ki67, topoisomerase IIalpha and CD34, reinforced by clinical findings, can predict phyllodes tumours on core biopsy specimens.
authors: Department of Pathology, Singapore General Hospital, Outram Road, Singapore.
authors: Ana Richelia
authors: AR
authors: Jara-Lazaro
authors: Meenakshi
authors: M
authors: Akhilesh
authors: Aye Aye
authors: AA
authors: Thike
authors: Philip Chi-Wai
authors: PC
authors: Lui
authors: Gary Man-Kit
authors: GM
authors: Tse
authors: Puay Hoon
authors: PH
authors: Tan
mesh_terms: D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D003557:Phyllodes Tumor / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D011237:Predictive Value of Tests; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D004250:DNA Topoisomerases, Type II