What is the pathology caused by acute cholecystitis?

Usually gallbladder distention, stone in cystic duct, after opened we see inflammatory exudate and pus (rarely) Later disease, bile pigments are replaced by thin mucoid pus/blood. If left untreated, and cystic duct still obstructed, lumen of gall bladder is distended and w/clear mucoid fluid (hydrops of gallbladder) If resected and no gall stones, we should look for vasculitis/ cholesterol embolus.