Urinary microscopy

From IDWiki

Interpretation

Syndrome Urine Sediment Urine Analysis
Prerenal AKI bland, hyaline casts, a few fine granular casts, occasional renal tubular epithelial cells ± protein
ATN renal tubular epithelial cells and casts, course granular casts, "muddy brown" casts ± protein
AIN white blood cells and casts, renal tubular epithelial cells and casts, red blood cells and occasional casts ±protein, +leukocyte esterase, + blood
Nephritic syndrome dysmorphic RBCs (acanthocytes), red cells and casts, white cells and casts + protein, ++ blood
Nephrotic syndrome lipid droplets, oval fat bodies, birefringent Maltese cross, lipid laden casts, cholesterol crystals +++protein
Crystalline nephropathy crystals, renal tubular epithelial cells, white and red cells, may have white cells engulfing crystals ± blood, ± LE
Osmotic nephropathy swollen renal tubular epithelial cells with cytoplasmic vacuoles, renal tubular epithelial cell and granular casts ±protein

Urinary Casts

Cast Causes
Acellular Casts
Hyaline non-specific
Granular prerenal AKI, ATN, exercise
Waxy advanced CKD
Fatty nephrotic syndrome
Pigment AKI from rhabdomyolysis or hemolysis, ATN
Cellular Casts
RBC glomerulonephritis
WBC pyelonephritis, proliferative glomerulonephritis
Epithelial cell prerenal AKI, ATN, glomerulonephritis, nephrotic syndrome

Further Reading

  • Cavanaugh C, Perazella MA. Urine Sediment Examination in the Diagnosis and Management of Kidney Disease: Core Curriculum 2019. Am J Kidney Dis. 2019 Feb;73(2):258-272. doi: 10.1053/j.ajkd.2018.07.012. Epub 2018 Sep 21. PMID: 30249419.