A tophus (Latin: "stone", plural tophi) is a deposit of crystallised monosodium urate in people with longstanding hyperuricemia. At this stage, most have already developed symptoms of the associated crystal arthropathy known as gout. Tophi form in the joints, cartilage, bones, and other places throughout the body. Sometimes, tophi break through the skin and appear as white or yellowish-white, chalky nodules. Without treatment, tophi may develop on average about ten years after the onset of the… (More on Tophus)