[Cytology of the urinary tract. A modern investigation method?]

Urinary cytology is used in the detection of nephrologic and uro-oncologic diseases. The advantages and limitations of cytology for the detection and follow-up of bladder cancer have been well known since Papanicolaou. The low sensitivity of urinary cytology, especially in the detection of more frequent urothelial tumors with low malignancy potential, led to the development of a number of new tumor markers. Nevertheless, the ideal tumor marker for bladder cancer has not yet been found. Cystoscopy combined with cytology is still the most widely accepted method for bladder cancer screening. The acceptance of this method can be improved by the use of case-specific preparation methods of a variety of materials. In addition to the follow-up of bladder cancer, urinary cytology is also used in the follow-up of renal transplant patients and therefore remains a worthwhile method leading to clinically relevant diagnoses.