Critical appraisal of stromal CD10 staining in fibroepithelial lesions of breast with a special emphasis on expression patterns and correlation with WHO grading.

Abstract

Fibroepithelial lesions of the breast are classified into fibroadenoma and phyllodes tumor (PT). Although WHO has established a well-defined grading system for PT, dilemma of discriminating borderline from malignant PT still exists. Stromal CD10 is a known poor prognostic factor in invasive breast cancer, its expression in fibroepithelial lesions of the breast is not well-documented. Till date, only one study has correlated the CD10 staining score with tumor grade in PT. To evaluate whether the differences in expression patterns of CD10 and staining intensity correlate with the degree of malignancy in fibroepithelial tumors of the breast. This is a retrospective study in which stromal CD10 expression was studied in 75 cases of fibroepithelial lesions of the breast using immunohistochemistry. Statistical analysis was performed using Chi-square test. There was a statistically significant trend of increasing stromal expression of CD10 with increasing degree of malignancy (P = 0.001). CD10 staining pattern and its scoring can assist the pathologist to accurately grade the PT of the breast for adequate treatment and can also be used as a target for the development of novel therapies.