They are named for their waxy or glossy appearance. They often appear brittle and cracked. Fatty casts are found in the nephrotic syndromes generally, diabetic nephropathy, other forms of chronic renal diseases, and glomerulonephritis. The fat droplets originate in renal tubular cells when they exceed their capacity to reabsorb protein of glomerular origin. Their inclusions have the features and significance of oval fat bodies.
Broad casts originate from dilated, chronically damaged tubules or the collecting ducts.
They can be granular or waxy. Spermatozoa may be seen in male urine related to recent or retrograde ejaculation.