Papillary transitional-cell carcinoma of the upper urinary tract: a cytological review.

Urinary cytology is a well-accepted diagnostic procedure for bladder carcinomas but it is utilized less frequently for diagnosis of upper urinary tract tumors. Accurate diagnosis depends on a suitable specimen as well as knowledge of diagnostic traps. This review article with several case studies emphasizes the various techniques used to obtain optimal samples, correct interpretative criteria, and diagnostic pitfalls. Technological advances for objective grading and predicting the biological behavior of tumors are also discussed.