What is the treatment post-surgery for cystosarcoma phylloides?

Depends: This depends on a variety of factors: was it benign, intermediate or malignant? Are there adequate margins? I highly recommend you speak to your surgeon, hopefully you have a breast specialst surgeon. You should also keep a copy of the pathology report for your personal records.

Phyllodes Tumor: Cystosarcoma phyllodes may be benign or malignant. A complete removed Benign phyllodes requires no addition treatment, just ongoing monitoring for recurrence. A completely removed Malignant phyllodes tumor may still require radiation to further reduce the risk of recurrence. Chemotherapy might be needed if there is evidence of spread (metastasis) to other parts of the body.