Genitourinary cytology.

Urinary cytology is a very accurate method of diagnosis of higher grade papillary urothelial carcinomas, carcinoma in situ, and clinically occult tumors of the renal pelvis and ureters. Most lower grade transitional cell neoplasms cannot be diagnosed cytologically with certainty. Fine needle aspiration biopsy (FNAB) of the prostate is an accurate method of diagnosis of malignancy in moderately and poorly differentiated adenocarcinomas; however, the diagnosis of well-differentiated tumors is difficult and, in most cases, impossible on FNAB material. FNAB is of value in the diagnosis of renal and testicular neoplasms in selected patients, in monitoring cellular rejection and determination of the impact of therapy in renal transplant patients, and in evaluation of male infertility. The limitations and pitfalls of these diagnostic cytologic methods are discussed.