An improved technic for examining urinary casts and a review of their significance.

Casts represent an important, diagnostic component of urinary sediment, and may signal renal parenchymal disease in asymptomatic individuals. Accurate, precise identification of certain casts may be difficult due to poor visualization by current technics. Casts from freshly voided urine specimens, cytocentrifuged and stained by the Papanicolaou method, can be visualized optimally from permanent slide preparations. The genesis of these casts and their diagnostic potential related to renal disease and acute renal allograft rejection are discussed.