Solid, tubular deposits in the urine, usually cast off from the walls of kidney tubules.

Gelled protein particles on the walls of kidney tubules that break off and are washed out by urine. The presence of casts in urine is an abnormal finding caused by kidney disease.

A cluster of cells or proteins formed in the kidney and excreted in the urine. Red blood cell casts usually indicate the presence of active vasculitis within the kidney. Kidney vasculitis is also known as glomerulonephritis.

Casts are plaster copies taken from objects. Traditionally, art students made drawings from casts. The intention of the cast was to teach the eyes "ideal beauty" of the human form, as well as, the art of drawing. Since plaster casts are white, they give the beginning artist a solid object devoid of color. Casts were used before the student graduated to drawing from life, giving them a basic solid knowledge of drawing before using color.

the preserved sediment or rock that fills a mold or impression, taking the shape of the once living organism.

Fossils formed when water containing minerals leaks into a mold. The minerals harden to form a copy of the original structure or organism.