Precancerous lesion of gall bladder is

Ans is 'a' ie Porcelain gall bladder "The calcified porcelain' gallbladder is associated with more than a 20% incidence of gallbladder carcinoma. These gallbladders should be removed, even if the patients are asymptomatic" - Schwartz SurgeryMirizzi SyndromeBiliary obstruction may occur in cases of acute cholecystitis, as a result of external compression of the CBD by a large stone impacted in the Hartman pouch and the associated intense pericholecystic inflammatory process; this is termed Mirizzi Syndrome. (Washington Manual of Surgery, 4/e, p 310)