Endothelin-1 expression correlates with atypical histological features in mammary phyllodes tumours.
OBJECTIVE
Endothelin-1 expression is increased in infiltrating duct carcinoma and is associated with larger tumour size, higher histological grade and lymphovascular permeation. This has not been evaluated in phyllodes tumours, which are uncommon fibroepithelial lesions with potential for local recurrences or distant metastasis. While the grading of phyllodes tumours depends on a combination of histological parameters, prediction of their behaviour remains difficult.


METHODS
A large series of 461 phyllodes tumours (291 benign, 115 borderline malignant and 55 frankly malignant) were evaluated for endothelin-1 expression in both the epithelial cells and stromal cells by immunohistochemistry; results were correlated with the tumour grade.


RESULTS
For benign phyllodes tumours, the epithelial staining of endothelin was negative, weak, moderate and strong in 6%, 26%, 15% and 53% of cases respectively; results were 4%, 18%, 19% and 59% respectively for borderline and 6%, 18%, 6% and 70% respectively for frankly malignant tumours. For the stromal staining, the negative, weak, moderate and strong staining was 32%, 19%, 18% and 31% respectively for benign phyllodes, 24%, 13%, 10% and 53% respectively for borderline and 8%, 16%, 17% and 59% respectively for frankly malignant tumours. There was correlation between epithelial and stromal staining, and the stromal staining correlated with histological features of stromal cellularity, stromal cell nuclear pleomorphism, margin status and stromal overgrowth.


CONCLUSIONS
These observations suggest a close relationship between the epithelial and stromal elements in phyllodes tumours; endothelin may play a significant role in the malignant progression of phyllodes tumours.
Tse
Gary M
GM
Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong. garytse@cuhk.edu.hk
Chaiwun
Benjaporn
B
Lau
Kin-Mang
KM
Scolyer
Richard
R
Lee
C Soon
CS
Karim
Rooshdiya Z
RZ
Putti
Thomas C
TC
Law
Bonita K
BK
Lui
Philip C
PC
Tan
Puay Hoon
PH
D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D019332:Endothelin-1 / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D003557:Phyllodes Tumor / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000473:pathology
D019332:Endothelin-1; D009363:Neoplasm Proteins