Cytology of the Urinary Tract: Specimen Sampling, Preparation, Adequacy, and Normal Cellular Components

Abstract

Urine evaluation is one of the oldest tests used in ancient medicine. Cytologic examination of urine is a simple, non-invasive, cost effective, and reliable method to uncover a wide variety of reactive and neoplastic processes in urothelium. Urinary tract lesions are often multifocal, may be inapparent on cystoscopic examination or inaccessible to directly biopsy. Thus, urine cytology remains one of the most common methods for the initial diagnosis of urothelial carcinoma that may be manageable with early detection. In this article we review indications for urine cytology, sampling techniques, preparatory methods, adequacy, and elements of normal urine.