Because of their low refractive index, the best microscopy to use is phase-contrast which enhances their visibility. However, these microscopes add costs to the analysis of the urine. While most hyaline casts are cigar-shaped, those formed in the Loop of Henle may have a tapered tail on one end. These are called cylindroids and have the same significance as hyaline casts. In disease states as many as 30 hyaline casts per low power field is common.
Hyaline casts dissolve quite readily in alkaline urine.
Note its cigar shape and how difficult it is to see because it blends into the background. Also note the mucus threads that are scattered throughout and the squamous epithelial cell in the lower left corner. All rights reserved.