Acute and chronic cholecystitis, cholangitis/cholangiohepatitis. Liver abscess. Etiology & pathogenesis. Microscopic & gross pathomorphology
Acute and chronic cholecystitis
Cholecystitis is inflammation of the gallbladder. It may be chronic, acute or acute superimposed on chronic. It is almost always due to gallstones (see below).
In acute cholecystitis the gallbladder is enlarged, tense, bright red and often has subserosal hemorrhage with a fibrinous cover (or fibrinopurulent in severe cases). 90% of cases are due to blockage of the neck of the gallbladder or the cystic duct. The gallbladder may be filled with cloudy bile that may contain fibrin, blood and pus, where there is mostly pus this is empyema of the gallbladder. In the most severe cases the gallbladder can become gangrenous.
In chronic cholecystitis morphological changes are highly variable, and often subtle. Gallbladder may be contracted, enlarged or normal size, ulcerations are infrequent, but the gallbladder wall is generally thickened from fibrosis.
H&E: Rokitansky–Aschoff sinus in chronic cholecystitis – the mucosa (top) dips down between the pink smooth-muscle bundles of the wall towards the subserosal fat.
Image: “Rokitansky-Aschoff Sinus, Gallbladder (3704042503)” by Ed Uthman from Houston, TX, USA, CC BY 2.0, via Wikimedia Commons.
Remember: the microscopic hallmark of chronic cholecystitis is Rokitansky–Aschoff sinuses – outpouchings of the mucosa pushed through the thickened muscular wall. In long-standing cases the wall may calcify (“porcelain gallbladder”), which raises the risk of gallbladder carcinoma.
The vast majority of acute cholecystitis is due to cholelithiasis. The stones block the duct and cause chemical irritation, causing hydrolysis of biliary lecithin to lysolecithin, toxic to the mucosa. Chronic cholecystitis is generally due to non-obstructive gallstones that have irritated and damaged the inner mucosa. Additionally, chronic cholecystitis can be due to bacterial infection (such as e.coli).
Symptoms of the acute form are right subcostal pain and tenderness, the chronic form has less pain and is generally recurrent attacks of epigastric pain, nausea, vomiting and intolerance for fatty foods.
Cholangitis
This is inflammation of the bile duct. It is generally found along with choledocholithiasis, which is when stones are in the bile ducts. Stones in the bile duct may not cause full obstruction, instead the symptoms can be liver abscess, chronic liver disease with secondary biliary cirrhosis, cholecystitis, cholangitis or full biliary obstruction.