5. The image is of a granular cast. Granular casts do not have a reference range and when seen are pathological. In patients with tubular problems, renal tubular cells are degraded and their intracellular contents are released into the tubular lumen and they become embedded as the granules seen within the casts. The presence of granular casts can be ominous as it indicates decreased urinary output, and thus a problem within the tubules. These casts are often seen in patients with renal tubular problems.

---