[Cystosarcoma phylloides of the breast. A retrospective analysis of 12 cases].

INTRODUCTION: Phyllodes tumours, also known as cystosarcoma phyllodes (CSP), are rare fibroepithelial tumours with an incidence of 0.3-1.0% of all breast neoplasms. CSP tends to recur locally and metastasizes haematogenously. The treatment of CSP remains controversial. The present study demonstrates the recent experiences in diagnosis, therapeutical management and clinical follow-up of this disease.

MATERIALS AND METHODS: Twelve female patients who developed CSP from 1982 to 1994 were recalled for clinical assessment and examined for local recurrence or metastatic disease. All histological samples from cases of CSP were evaluated by a single pathologist who was blinded to the patients' histories. The tumours were classified according to international criteria of three types of tumour status: benign CSP, borderline type tumours and malignant tumours.

RESULTS: The average age of disease was 46 years. Three patients had benign tumours. There was one borderline type of tumour and eight malignancies. Six patients with malignant CSP underwent mastectomy and axillary dissection. In two cases of malignant CSP simple mastectomy was performed. In two cases of malignancy the operation was followed by radiation therapy. The borderline type of tumour and the benign CSP were treated by tumour removal, segmental resection or subcutaneous mastectomy. In one case of benign CSP two more benign recurrencies ocurred 18 months after the initial operation. Preoperative determination of the tumour marker CEA was normal. The tumour marker CA 15-3 was only elevated in one case. The growth fraction varied from 5-40%. In 8/8 patients the oestrogen and progesterone receptors were negative. We could not find any correlation between the development of cystosarcoma phyllodes and oral contraceptives, nicotine use, diabetes mellitus, age of menarche, allergies, or family history of cancer.

CONCLUSION: The clinical finding of a large, firm, non-tender, well-defined, mobile tumour with gradual growth should lead to a suspicion of a phyllodes tumour. Our results and the review of the current literature lead to the following therapeutic recommendations: 1. Benign phyllodes tumour warrants wide local excision with a 2 cm tumour-free zone. 2. Borderline malignant phyllodes tumours should be treated via simple mastectomy. 3. Axillary dissection is recommended only if nodes are palpable. 4. Adjuvant radiation is necessary, if wide local spread of the tumour is present and a resection of the lesion with a 2 cm tumour-free zone is not possible. Close follow-up is mandatory.