MKI67 and malignant breast phyllodes tumor: A variety of other immunohistochemical markers, such as Ki-67 p53, VEGF, EGFR, CD10; flow cytometry analysis of ploidy and S-phase, cytogenetic studies and quantitative measures of stromal cellularity, stromal-to-epithelial ratio, mitotic rate, stromal overgrowth, and mean nuclear diameter were studied, in order to distinguish cellular fibroadenomas from benign phyllodes tumors and subclassify benign, borderline, and malignant phyllodes tumors.