by Jason Wasserman MD PhD FRCPC
July 4, 2023
Acute cholecystitis means active or ongoing inflammation of the gallbladder, a small pear-shaped organ that sits just under the liver.
The most common cause of acute cholecystitis is the presence of a gallstone in the cystic duct, a small tube that allows for the flow of bile out of the gallbladder. Most gallstones are made out of cholesterol, and they form inside the gallbladder.
The most common symptom of acute cholecystitis is abdominal pain that is worst shortly after eating. The pain is often described as stabbing or sharp, and it can be felt just below the ribs on the right side of the abdomen or in the back.
The gallbladder is a small, pear-shaped organ located beneath the liver in the upper right side of the abdomen. It is part of the digestive system. The primary function of the gallbladder is to store and concentrate bile, a yellowish-green fluid produced by the liver.
Bile is made up of salts, cholesterol, bilirubin (a waste product of red blood cell breakdown), and other substances. The liver produces bile continuously, but the gallbladder stores it and releases it in response to signals from the digestive system, particularly when fatty foods are consumed. Bile aids in the breakdown and emulsification of fats, making them easier to digest and absorb. Bile salts also help in the absorption of fat-soluble vitamins.
Pathologists use the term cholelithiasis to describe gallstones which are hard, stone-shaped collections of biological material that build up in the gallbladder. Most gallstones are made of cholesterol that comes from the liver. Gallstones can also be made up of bilirubin, which forms when red blood cells break down, or the mineral calcium. Gallstones can cause acute cholecystitis by filling the gallbladder and preventing it from contracting normally or by blocking one of the tubes that connect the gallbladder to the small bowel.
In pathology, the term cholesterolosis is used to describe immune cells called histiocytes that are filled with cholesterol. Cholesterolosis is commonly seen in acute cholecystitis.
Chronic cholecystitis is diagnosed after the gallbladder is removed in a procedure called a cholecystectomy. This surgical procedure is usually performed after imaging, such as an ultrasound or CT scan of the gallbladder, shows features consistent with acute cholecystitis.
When examined under the microscope, the gallbladder of an individual with acute cholecystitis shows evidence of ongoing or acute inflammation. Specifically, a variety of inflammatory cells, including neutrophils, lymphocytes, plasma cells, and histiocytes, are usually seen in the mucosa, the thin layer of tissue that covers the inside of the gallbladder.