Urinary sediment: Microscopic examination

Microscopic examination of urine sediment after centrifugation shows:

• Normal:         few cells
• Red cell cast:         hematuria due to glomerular disease
• White cell cast: E.g. during pyelonephritis
• Bacteriuria: UTI, pyelonephritis

Crystals (in acidic urine):

1. Calcium oxalate – star like or envelope like or dumbell shaped
2. Uric acid crystals - yellow to red brown crystals shapes like rosettes, prisms, or rhomboids.
3. Cholesterol crystals - clear, flat, rectangular plates with notched corners – E.g. in nephrotic syndrome and chyluria.
4. Cysteine crystals appear colorless refractile hexagons.
5. Crystals (in alkaline urine) - Amorphous phosphate - fine, colorless mass like sand
6. Calcium carbonate crystals - colorless dumbbells or spheres
7. Triple phosphate crystals - colorless prism of 3-6 sides, resembling coffin lids.