[Bladder carcinosarcoma. A clinical case].
Presentation of a new case of vesical carcinosarcoma in a 49 year-old male patient. The tumour's pathoanatomical study showed an epithelial pattern of transitional and squamous cells and a sarcomatous pattern composed of rabdomiosarcoma, osteochondrosarcoma and pleomorphous indifferentiated sarcoma with giant multinuclear cells. Histogenesis, signs and symptoms, and treatment, as well as the need of performing an immunohistochemical study for its diagnosis are discussed.