Waxy casts appear as cylinders of smooth, highly refractile material. They are homogeneous with sharp, defined edges and usually squared-off ends. Cracks may occur within the cast, giving it a segmented appearance. Some believe waxy casts are the final stage of degeneration of the fine granules of granular casts. This finding implies localized nephron obstruction since the granules need time to degrade.
Waxy casts are seen in chronic renal failure and acute and chronic renal allograft rejection.
Inclusive waxy casts, sometimes referred to as renal failure casts, are created in the dilated tubules of end-stage renal disease.
