Your pathology report for acute cholecystitis

by Jason Wasserman MD PhD FRCPC
September 23, 2025

Acute cholecystitis refers to the sudden and active inflammation of the gallbladder. The gallbladder is a small, pear-shaped organ located just beneath the liver in the upper right side of the abdomen. Inflammation happens when the gallbladder wall becomes swollen and irritated, usually because something is blocking the normal flow of bile.

What is the function of the gallbladder?

The gallbladder is part of the digestive system. Its main job is to store and concentrate bile, a yellowish-green fluid made by the liver.

Bile is made up of salts, cholesterol, bilirubin (a substance produced when red blood cells break down), and water. When you eat a meal, especially one that contains fat, the gallbladder squeezes and releases bile into the small intestine. The bile helps break down fat so that the body can digest and absorb it properly, and it also helps the body absorb essential fat-soluble vitamins (A, D, E, and K).

What causes acute cholecystitis?

The most common cause of acute cholecystitis is a gallstone blocking the cystic duct, a small tube that allows bile to leave the gallbladder. When the duct is blocked, bile cannot flow out. This buildup of bile causes the gallbladder to swell, leading to irritation and inflammation of its wall.

Most gallstones are made of cholesterol that comes from the liver, but some are made of bilirubin or calcium.

In rare cases, acute cholecystitis can be caused by other problems, such as tumors, scarring, or infections, but gallstones are by far the most common reason.

What are the symptoms of acute cholecystitis?

The most common symptom is sudden pain in the upper right side of the abdomen, often just below the ribs. The pain usually starts after eating, especially fatty foods, and may spread to the back or right shoulder. It is often described as sharp or stabbing.

Other possible symptoms include:

• Nausea or vomiting.

• Fever or chills.

• Tenderness over the right side of the abdomen.

• Loss of appetite.

If untreated, the pain and inflammation can become severe and lead to complications.

What does cholelithiasis mean?

Cholelithiasis is the medical term for gallstones. Gallstones are hard, stone-like collections of material that form inside the gallbladder. Most are made of cholesterol, but they can also contain bilirubin or calcium.

Gallstones can cause acute cholecystitis by blocking the cystic duct or by filling the gallbladder, preventing it from contracting and releasing bile normally.

How is acute cholecystitis diagnosed?

Doctors usually begin with imaging tests such as an ultrasound or CT scan, which can show swelling, gallstones, or other signs of gallbladder disease.

The diagnosis is confirmed after the gallbladder is removed in a surgery called a cholecystectomy. A pathologist examines the gallbladder under the microscope to look for features of acute inflammation.

What does acute cholecystitis look like under the microscope?

When examined under the microscope, a gallbladder with acute cholecystitis shows signs of acute inflammation. The wall of the gallbladder, especially the inner lining called the mucosa, is filled with inflammatory cells. These include neutrophils (a type of white blood cell that responds quickly to infection), lymphocytes, plasma cells, and histiocytes.

The tissue may also appear swollen, with damage resulting from the buildup of bile and pressure from the blocked duct.

What does cholesterolosis mean?

Cholesterolosis is a change sometimes seen in the gallbladder where immune cells called histiocytes become filled with cholesterol. Under the microscope, this can make the inside of the gallbladder wall appear speckled with tiny yellow spots, sometimes referred to as a “strawberry gallbladder.” Cholesterolosis is often found in gallbladders removed for acute cholecystitis.

Questions to ask your doctor

If your gallbladder has been removed and your pathology report shows acute cholecystitis, you may find it helpful to ask your doctor the following questions:

• Does my pathology report show gallstones (cholelithiasis)?

• Was there any other change in the gallbladder, such as cholesterolosis or chronic inflammation?

• Does the report show any complications, such as damage to the gallbladder wall?

• Does my report rule out cancer or other unexpected findings?

• Now that my gallbladder has been removed, do I need to make any changes to my diet or lifestyle?

• Are there any specific symptoms to watch for after surgery, such as digestive issues?

• Do I need any follow-up tests or treatment?