Predictors of phyllodes tumours on core biopsy specimens of fibroepithelial neoplasms.
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.
Jara-Lazaro
Ana Richelia
AR
Department of Pathology, Singapore General Hospital, Outram Road, Singapore.
Akhilesh
Meenakshi
M
Thike
Aye Aye
AA
Lui
Philip Chi-Wai
PC
Tse
Gary Man-Kit
GM
Tan
Puay Hoon
PH
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
D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D004250:DNA Topoisomerases, Type II