The standard treatment for locally advanced urothelial bladder carcinoma is radical cystectomy or chemoradiation. Sarcomatoid urothelial carcinoma, a rare tumour, is treated with radical cystectomy because the response to radiation therapy alone is poor in other sarcomas. We report a case of high-grade hyperinvasive urothelial bladder carcinoma with sarcomatoid differentiation. The patient refused cystectomy, and so a chemoradiation regimen was devised for her treatment. She completed the regimen and has since demonstrated a complete response to chemoradiation therapy clinically and pathologically by biopsy. The patient has therefore been able to attain a complete response while preserving a functional bladder.
