- A concretion in the gallbladder or a bile duct, composed chiefly of a mixture of cholesterol, calcium bilirubinate, and calcium carbonate, occasionally as a pure stone composed of just one of these substances. SYN: biliary calculus, cholelith.- opacifying gallstones gallstones becoming roentgenographically opaque after prolonged exposure to cholecystographic contrast mediums.- silent gallstones gallstones that cause no symptoms and are discovered by radiographic or ultrasound examination at the time of operation or autopsy.
* * *gall·stone 'gȯl-.stōn n a calculus (as of cholesterol) formed in the gallbladder or biliary passages called also biliary calculus, cholelith
* * *n.a hard mass composed of bile pigments, cholesterol, and calcium salts, in varying proportions, that can form in the gall bladder. The formation of gallstones (cholelithiasis) occurs when the physical characteristics of bile alter so that cholesterol is less soluble, though chronic inflammation of the gall bladder (see cholecystitis) or diminished contractility may also be a contributory factor. Gallstones may exist for many years without causing symptoms. However, they may cause severe pain (see biliary colic) or they may pass into the common bile duct and cause obstructive jaundice or cholangitis Gallstones are usually diagnosed by ultrasonography, but those containing calcium may be seen on a plain X-ray (opaque stones). Cholelithiasis is usually treated by surgical removal of the gall bladder (see cholecystectomy) or by removing the stones themselves, which can be either dissolved using bile salts given by mouth or shattered by ultrasound waves. There is no need for treatment if the stones are causing no symptoms.
* * *gall·stone (gawlґstōn) a concretion formed in the gallbladder or bile duct; the usual composition is cholesterol, a blood pigment liberated by hemolysis, or a calcium salt. Called also biliary calculus and cholelith. See also cholelithiasis.
Medical dictionary. 2011.