An in vitro method of determining the type of a fibroepithelial tumour of the breast in a biological sample is provided. The method comprises the steps of obtaining an expression profile of one or more genes selected from the group consisting of PRAME, ADH1 B, CTHRC1, NPTX2, NEFL, ABCA8, DAPL1, TP63_v2, COL17A1, GCNT2, CCL19, MMP3, FN1, TRERF1, TRIM29, TESC, KIF20A, UHRF1, HEPACAM2, APOD, SERHL2. KIF15, HOXD13, GAGE2B, CALML5, C2orf40, ADH1C, CYP1B1, SPAG11B, GRB7, UBE2C, SYNGAP1, TP63_v1, LAMB1, OR5P3, SPC25, SHISA2, SCARA5, LHX2, RORC, DPYSL4, CH25H, and CHST1 in a sample and determining the differential activity of the one or more genes relative to a control; correlating the differential activity of the one or more genes relative to the control to obtain a p-score; and determining the type of fibroepithelial tumour based on the p-score, wherein a p-score of less than 0.5 is indicative of a fibroadenoma and a p-score of 0.5 and above is indicative of phyllodes tumour. Particularly, the said method is exemplified using an expression profile of five genes comprising of PRAME, FN1, CCL19, ABCA8 and APOD. A method for managing the treatment of a subject with a fibroepithelial tumour of the breast is also provided as well as a kit when used in the methods of the present invention.