Lavage of cytology of the renal pelvis and ureter with special reference to tumors.

Lavage cytology was done in 101 patients with radiological filling defects in the ureter and renal pelvis. This simple and inexpensive technique is valuable in the preoperative diagnosis of tumors of the ureter and renal pelvis. In our series it was possible to recognize clearly 29 of 36 such tumors (80.5 per cent) through preoperative lavage cytology. No falsely positive diagnoses were made. Lavage cytology failed in 6 patients with hypernephroma. The diagnostic reliability of lavage cytology with urothelial tumors is far greater than that of exfoliative urine cytology and reaches almost equally good results as brush biopsy.