Urine Casts

Question 1

Describe Hyaline Cast

Answer 1

Composition: Pure Tamm-Horsfall protein
Appearance: Clear, colorless, cylindrical
Clinical Significance: Can be normal (especially after exercise, dehydration, or stress)
Associated Conditions: Mild renal disease, fever, strenuous exercise

Question 2

Describe Red Blood Cell Cast

Answer 2

Appearance: Yellow-brown with visible RBCs
Clinical Significance: Always pathological
Associated Conditions: Glomerulonephritis, vasculitis, lupus nephritis
Indicates: Bleeding within the nephron

Question 3

Describe White Blood Cell Cast

Answer 3

Appearance: Casts containing white blood cells
Clinical Significance: Indicates inflammation or infection in the kidney
Associated Conditions: Pyelonephritis, interstitial nephritis
Differentiation: Seen with other signs of infection (fever, flank pain)

Question 4

Describe Granular Cast

Answer 4

Appearance: Coarse or fine granules
Origin: Degenerated cellular casts or protein aggregates
Clinical Significance: Can be normal or pathological
Associated Conditions: Chronic kidney disease, acute tubular necrosis

Question 5

Describe Waxy Cast

Answer 5

Appearance: Smooth, refractile, with sharp edges; often cracked
Clinical Significance: Always pathological
Indicates: Chronic kidney disease, end-stage renal disease
Sign of: Long-standing tubular stasis

Question 6

Describe Fatty Cast

Answer 6

Appearance: Casts containing fat droplets (may show “Maltese cross” under polarized light)
Clinical Significance: Pathological
Associated Conditions: Nephrotic syndrome
Indicates: Lipiduria due to heavy proteinuria

Question 7

Describe Renal Epithelial Tubular Cast

Answer 7

Appearance: Renal tubular epithelial cells within a cast
Clinical Significance: Indicates tubular damage
Associated Conditions: Acute tubular necrosis, viral infections, nephrotoxicity

Question 8

Describe Broad Cast

Answer 8

Broad casts or “renal failure” casts are associated with end-stage renal disease. They are formed in the collecting ducts due to urinary stasis and are two to six times the size of other types of casts. Any kind of cast can be a broad cast.