Cholelithiasis. Types of stones. Complications. Carcinoma of the gallbladder and extrahepatic bile ducts
- Gallstones are broken down into two main types:
- Cholesterol gallstones (70-90%) - these are yellowish in colour, contain undissolved cholesterol and are mostly radiolucent (only 10-20% contain enough calcium carbonate to be visible on X-ray)
- Pigment gallstones that can arise anywhere in the biliary tree (not just the gallbladder) are a browner colour thanks to the bilirubin they contain. They also have glycoproteins and proteins. Black pigment stones are often radio-opaque; brown ones are radiolucent.
- All gallstones are formed by one of the following:
- Too much cholesterol
- Too much bilirubin
- Inability of the gallbladder to empty
- Risk factors
- Forty +
- Female
- Fat
- Fertile (estrogen levels)
- Complications
- Inflammation of gallbladder (cholecystitis)
- Inflammation of pancreas (pancreatitis)
- Inflammation of bile ducts (cholangitis)
Gross: opened gallbladder full of stones – a few large yellowish (cholesterol-rich) stones and many small, dark, faceted mixed stones; the facets form where stones press against each other.
Image: “Gallstones” by Emmanuelm at en.wikipedia (Original text : Emmanuelm ( talk ) ), CC BY 3.0, via Wikimedia Commons.
Remember: pigment stones come in two kinds – black stones form in sterile gallbladder bile when bilirubin is high, e.g. chronic haemolysis (sickle cell disease, hereditary spherocytosis) or cirrhosis; brown stones form in infected intrahepatic or large bile ducts (E. coli, parasites such as Ascaris or liver flukes), mostly in Asia.
Carcinoma of the gallbladder
Carcinoma of the gallbladder is the most frequent malignant tumour of the biliary tract. Higher prevalence in women, thought to be tied into prevalence of gallstones. Tumours may be exophytic or infiltrating (more common) in growth, and appear as a area of diffuse thickening of the gallbladder wall. Most are adenocarcinomas, a small percent are SCC. Symptoms are vague, presents with jaundice, anorexia, abdominal pain and nausea.
We can also have cholangiocarcinomas (a type of adenocarcinoma) coming out of the hepatobiliary tree.