Malignant phyllodes tumours of the breast display increased stromal p53 protein expression.
OBJECTIVE
To determine the variation in p53 protein expression in phyllodes tumours and fibroadenomas of the breast.


RESULTS
Fifteen phyllodes tumours (six malignant, nine benign) and 20 fibroadenomas were examined for p53 expression by immunohistochemistry. Five of the six malignant phyllodes tumours showed moderate or strong p53 positivity at sites of peri-epithelial stromal condensation and atypia. All 20 fibroadenomas, nine benign phyllodes tumours and one malignant phyllodes tumour showed either negativity or focal weak nuclear positivity of scattered stromal cells.


CONCLUSIONS
Increased p53 immunoreactivity is present in malignant phyllodes tumours in contrast to benign phyllodes tumours and fibroadenomas. Malignant phyllodes tumours display a distinctive pattern of p53 immunostaining which may be of diagnostic value. These findings suggest that p53 protein may be important in the progression of benign to malignant phyllodes tumours.
Millar
E K
EK
Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, N.S.W., Australia.
Beretov
J
J
Marr
P
P
Sarris
M
M
Clarke
R A
RA
Kearsley
J H
JH
Lee
C S
CS
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D018226:Fibroadenoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D003557:Phyllodes Tumor / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
D016159:Tumor Suppressor Protein p53