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Cast Compilation
The image below represents different casts seen in urine at the same
magnification and lighting. Shown are hyaline, fatty, granular and waxy
casts.
Hyaline casts can be quite difficult to see in wet preparations of urine
sediments with light microscopy, even with the condenser of the microscope
racked down. They are much easier to visualize using phase contrast,
however phase is usually not available on most microscopes. They become
more visible with regular light microscopy if fat sticks to the protein
matrix (Tamm-Horsfall mucoprotein) that makes up the hyaline cast (image
B) or particulate material from degenerating cells is present within
the cast matrix (image C). Cellular casts have distinct cells within
the protein matrix - if the cells are of epithelial origin (i.e., not
WBCs or RBCs), they are called epithelial casts (images D and E). As
cells within the protein cast matrix break down, the cast becomes coarsely
(image E and F) then finely granular (image G). Waxy casts are the final
stage of cast degeneration (usually originating from cellular and granular
casts). Compared to hyaline casts, they are readily observable because
they have a smooth appearance, no internal texture, and are more refractile
than the surrounding urine.
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Legend:
A: Hyaline cast; B: Fatty cast;
C: Hyaline to finely granular cast; D:
Cellular cast;
E: Cellular to coarsely granular cast; F:
Coarsely granular cast; G: Finely granular cast;
H: Granular to waxy cast, I:
Waxy cast.
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Copyright ©
Cornell University
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