any of the various casts formed from gelled protein precipitated in the distal convoluted tubules and collecting ducts of nephrons and molded to the tubular or duct lumen which dislodge and pass into the urine; types named for their constituent material include acellular casts (e.g. granular, hyaline, waxy, or fatty casts) and cellular casts (e.g. red or white blood cell casts)