ABSTRACT
The primary objective of microscopic examination of urine sediment is to define the cellular elements which have entered the urinary tract, to identify casts and the elements included in them as they are formed in the tubules, and to interpret these findings, particularly in relation to renal dysfunction. The history of examination of urine sediment for particles of significance in the definition of health or disease began soon after the invention of the microscope by Van Leeuwenhoek. Most clinical pathology textbooks and most publications by nephrologists and urologists agree that there are a few red or white cells and an occasional cast present in normal urine. The examination of urine sediment under the high power field of the microscope has become so routine that most modern textbooks of clinical pathology only briefly describe the technique, even though it is a standard part of routine urinalysis in almost all laboratories.
