Urinary immunocytology—Promise or nonseller? A review with an opinion

Urine cytology is considered a valid diagnostic method of urological and nephrological diagnosis and follow-up, whereas immunohistochemistry is an indispensable adjunct to histopathology. The combination of both—urinary immunocytology—has, so far, only attained a marginal role. This review gives a state-of-the-art update of urinary markers and relevant epitopes, elucidates some methodological pitfalls, and gives an outlook on the promise of urinary immunocytology today. It suggests that morphological urine cytology should be amended by immunology in a mutual quest of urologists and pathologists to improve the diagnostic power of urine cytology. The cost-effectiveness of the method is considered. This review also sheds light on the age-old dispute among pathologists about the nature of urothelial carcinoma that is reflected in the frequent and controversial reclassifications of the disease.