Poorly differentiated muscle-invasive giant cell tumor of the bladder leads to unfavorable clinical outcome.

Urothelial carcinoma of the urinary bladder is a common clinical entity. Recently, researchers focused on the emerging clinical significance of histologic variants, because they may need special therapy and their prognosis differs. Hereby, we describe a case of a giant cell osteoclast-like urothelial carcinoma of the urinary bladder.