PIK3CA and Fibroadenoma: Mutational analysis in several cohorts showed higher rate of MED12 exon 2 hotspot mutations in fibroadenomas and lower grade phyllodes tumors, particularly benign phyllodes tumors27,29–31, while genetic aberrations in TP53, RB1, NF1, PIK3CA, ERBB4, and EGFR were more commonly found in malignant phyllodes tumors23,31–33.