In the retrospective analysis of our study group, we found a high percentage of haematogenous metastasis that was always accompanied with a very poor prognosis in malignant CSP patients. Those patients always died within a short period of time. Two of these patients showed, while they underwent initial surgery, no metastatic suspect lesions and underwent R0 resection; both received a radical mastectomy. One patient already showed lung metastasis while undergoing first line surgery, because she initially declined surgery. We therefore speculate that postoperative adjuvant chemotherapy could lead to a favorable outcome in high risk patients, concerning the development of haematogenous metastasis.