Epithelial Cell Casts

Epithelial casts are formed by adhesion of desquamated dead epithelial cells of the renal tubule lining. Epithelial cells can adhere in random order or in sheets and are distinguished by large, round nuclei and a lower amount of cytoplasm. Epithelial cell casts reflect damage to the renal tubules and can be seen in acute tubular necrosis and toxic ingestion, such as from mercury, diethylene glycol, or salicylate. In each case, clumps or sheets of cells may slough off simultaneously, depending of the focality of injury. Cytomegalovirus and viral hepatitis are organisms that can cause epithelial cell death as well.

Epithelial casts, or cellular casts, are found in urine when renal diseases, such as ischemic acute tubular necrosis, infarction, or nephrotoxicity, cause degeneration and necrosis of tubular epithelial cells. The presence of these casts indicates acute tubular injury but does not indicate the extent or reversibility of the injury. A common scenario is the patient with decreased renal perfusion and oliguria secondary to severe dehydration. Ischemic injury results in degeneration and sloughing of the epithelial cells.

Epithelial casts