Renal epithelial fragments in urine sediment.

In this cytomorphologic study, the diagnostic criteria for recognizing renal epithelial fragments are given based upon urine sediment examinations with histologic correlation. The study included individuals without urine system disease and patients with acute allograft rejection, acute tubular necrosis, papillary necrosis and renal infarction. Exfoliated renal epithelial fragments are accurately identified by th following configurational characteristics: (1) epithelium attached to or molded by renal casts, (2) epithelial encasement of casts, (3) cylindrical ("sleevelike") epithelium, (4) epithelial sheets with "honeycomb" arrangement and (5) epithelium containing spindle or elongate cells.