Granular casts are composed of plasma protein aggregates and cellular remnants. Granular casts appear as irregularly-shaped cylinders of coarse or fine, highly refractive particles. A granular cast containing coarse brown granules is indicated by the yellow arrow in the image on the right (brightfield, 400X magnification).
The presence of an occasional granular cast is not considered pathologic.
Hyaline casts are also present in this field and are indicated by the blue arrows.