Introduction

The urinary system includes the kidneys, ureters, urinary bladder, and urethra. Pathologic conditions can affect any segment of the urinary system, but most lesions involve the kidneys or bladder, which will be the focus of this chapter. Ureteral and urethral lesions are rare and will only be discussed briefly near the end of the chapter.

In addition to sampling renal and bladder lesions, microscopic examination of urinary sediment can provide valuable information regarding urinary tract disease. Sediment examination is one part of a complete urinalysis, which also includes gross examination, specific gravity measurement, and dipstick analysis. A description and interpretation of the complete urinalysis are beyond the scope of this text.