RESUMEN
Carcinosarcoma or sarcomatoid carcinoma of the urinary bladder is a rare but aggressive bladder cancer characterized by malignant epithelial and mesenchymal components, with only a few cases reported in the literature so far. In this report, we discuss a case of a 74-year-old female nonsmoker who presented with intermittent hematuria and passage of clots in the last four months. Radiographic images showed an irregular mass lesion (6.2 x 6 cm) in the left lateral wall of the urinary bladder near to left vesicoureteral junction. The mass was completely removed with transurethral resection of the bladder tumor (TUR-BT). Histopathological study revealed high-grade carcinosarcoma, and immunohistochemistry showed diffuse positivity for vimentin, pan-cytokeratin (CK) and CK7, epithelial membrane antigen (EMA), and CK5/6. The patient declined radical cystectomy and only agreed to receive intravesical chemotherapy (gemcitabine), and she remains alive after more than four years of follow-up. Carcinosarcoma of the urinary bladder is a rare tumor primarily affecting older people, and it is most commonly treated with radical cystectomy and different combination treatments such as chemotherapy and radiation. However, tumor resection followed by intravesical chemotherapy may be an alternative option in the early stages of bladder carcinosarcoma for some patients, thereby avoiding the need for aggressive treatments, especially for elderly patients who decline to undergo radical surgery.