The importance of microscopic examination of the urinary sediment.

Urinalysis may provide evidence of significant renal disease in asymptomatic patients. The microscopic urinalysis is vital to making diagnoses in many asymptomatic cases, including urinary tract infection, urinary tract tumors, occult glomerulonephritis, and interstitial nephritis. Three-hundred-fifty-three consecutive urinalyses were performed in our Urinalysis Laboratory to discern the incidence of significant urinary findings not disclosed by macroscopic examination. One-hundred-seventy-two urines had negative macroscopic exams, but 52 of these had positive microscopic findings, an incidence of 30% (52/172). Furthermore, 15% (52/353) of all urines studied revealed significant urinary findings microscopically. An adequate examination of the urine must include a microscopic as well as a macroscopic examination.