[Pathogenesis, morphology, prognosis, clinical course and therapy of cystosarcoma phyllodes mammae (author's transl)]

Our investigation of 20 cases of C. ph. of the breast in women aged between 12 and 70 years yielded the following results: 1. In all cases a fibroadenoma or remnants of such a tumor were seen alongside with C. ph. A C. ph. therefore always develops on the base of a benign fibroadenoma of the breast. 2. The mitotic proliferation of the epithelium induces a proliferation of the myoepithelial cells which form the stromal portion of the tumor and can differentiate in to fibroblasts, lipoblasts, smooth muscle cells, reticulum cells, cartilage cells, osteoid cells or bone cells. The C. ph. of the female breast should thus be seen as an adenomyothelioma. Malignant degeneration of stromal cells possibly with haematogenous metastasis is observed in some cases. Concurrent malignant change of the epithelium (carcinosarcoma) is extremely rare and leads to lymph node metastases. 3. At the time being, there is no standardized and/or schematic treatment available. The therapy should be performed according to the size and growth of the tumor into the surrounding tissue, from simple excision to mastectomy. Radiation therapy ist not effective.