FIG. 35:  A second histologic variant is sarcomatoid carcinoma (carcinosarcoma).^[40]  These are biphasic tumors with a malignant spindle and epithelial cells.  Grossly, many tumors present as polypoid masses.  Nodal or distant metastases are frequent.  The tumor is often understaged, has a poor prognosis, and many of these patients die very soon.  The differential diagnosis from a true sarcoma and an invasive muscle tumor is essential.  In most cases these patients with T1 bladder cancer are best treated with an immediate radical cystectomy.