Malignant phyllodes tumours of the breast. A clinical and pathological analysis of 55 cases

55 cases of malignant phyllodes tumours of the breast are described. 36 patients (i.e. 65.5%) of the studied group survived 5 years with no evidence of disease after surgery. It was proved that a simple mastectomy is sufficient therapy for patients with tumour limited to the breast. Metastases to the axillary lymphatic nodes are very rare. The main reason for treatment failure is distant metastases in the lungs. The only prognostic factor in the studied group was the grade of histological malignancy, determined by such criteria as the ratio between the malignant sarcomatous tissue and that typical for phyllodes tumour, the degree of cell polymorphism, mitotic activity, and possible multidirectional differentiation (towards malignant neoplasms of soft tissue and bones).