Carcinosarcoma Arising From the Renal Pelvis: A Rare Case Report.

Carcinosarcoma is a malignant tumor of biphasic character consisting of epithelial and mesenchymal components. This rarely-seen tumor has an exceedingly aggressive nature. While it is rare in the urinary system, it appears even more rarely in the renal pelvis. Thus, there are few publications in the literature on carcinosarcomas originating from the renal pelvis. This paper presents a 42-year-old male patient with carcinosarcoma of the renal pelvis (CSRP), kidney stone disease, and a nephrocutaneous fistula who underwent radical nephrectomy and eventually died of metastatic disease. The rarity of the disease is the main obstacle to conducting comprehensive clinical trials. Therefore, it is of great importance to publish the identified carcinosarcoma of the renal pelvis cases.