Hyaline casts are formed in the absence of cells in the tubular lumen. They have a smooth
texture and a refractive index very close to that of the surrounding fluid. Reduced lighting is
essential to see hyaline casts. Lower the substage condenser.
When present in low numbers (0-1/LPF) in concentrated urine of otherwise normal patients, hyaline casts are not always indicative of clinically significant renal disease. Greater numbers of hyaline casts may be seen in association with proteinuria of renal (e.g., glomerular disease) or extra-renal (e.g., overflow proteinuria as in myeloma) origin. In such cases it has been proposed that the presence of excessive serum protein in the tubular lumen promotes precipitation of the Tamm-Horsefall mucoprotein. |
Last Updated: January 15, 1996