RTE cell casts appear as clear cylinders containing RTE cells. These casts indicate tubular damage. In some RTE cell casts, the RTE cells may appear in rows, indicating that the epithelium of an entire tubule has sloughed off.
Renal epithelial cell casts may be difficult to distinguish from WBC casts especially if the casts have begun to degrade. Phase-contrast microscopy or supravital stains may aid differentiation. The RTE cell cast shown in the image on the right was stained with supravital stain.