Gallbladder and Biliary Tract Diseases

Gallstone Genesis - Rocking the Ducts

• Core Imbalance: Bile constituents precipitate.
• Types:

  • Cholesterol Stones (~80%):

    • Patho: ↑Cholesterol, ↓Bile salts/Lecithin → supersaturation; nucleation; GB stasis.
    • Risk: 📌 4 F's (Fat, Female, Forty, Fertile), OCPs, fibrates, Crohn's, rapid weight loss.
    • Look: Yellow-green, often large, radiolucent (mostly).

  • Pigment Stones (~20%):

    • Black Stones:
      • Patho: ↑Unconjugated bilirubin (hemolysis, cirrhosis).
      • Composition: Calcium bilirubinate.
      • Look: Small, dark, brittle. Radio-opaque (~50-75%).
    • Brown Stones:
      • Patho: Infection (E. coli, parasites), stasis.
      • Composition: Ca-bilirubinate, cholesterol, Ca-palmitate/stearate.
      • Look: Soft, earthy, in ducts. Radiolucent.

⭐ Most common: Cholesterol stones (cholesterol monohydrate).

Gallbladder Grief - Inflamed & Irritated

• Acute Cholecystitis: Sudden inflammation; 90% due to gallstone in cystic duct.
  • Patho: Obstruction → inflammation → ischemia.
  • Clinical: RUQ pain, positive Murphy's sign, fever, ↑WBC.
  • Diagnosis: Ultrasound (wall thickness > 4mm, pericholecystic fluid, sonographic Murphy's). HIDA scan if USG equivocal.
  • Complications: Gangrene, perforation, emphysematous cholecystitis (gas-forming organisms; common in diabetics).
• Chronic Cholecystitis: From repeated acute attacks or chronic gallstone irritation.
  • Clinical: Recurrent RUQ pain, dyspepsia, fatty food intolerance.
  • Histopathology: Thickened fibrotic wall, chronic inflammation. Rokitansky-Aschoff sinuses (mucosal herniations into muscularis).
  • Complications: Porcelain gallbladder (calcification, ↑cancer risk), Mirizzi syndrome.
• Acalculous Cholecystitis: Inflammation without stones. Seen in critically ill patients (TPN, trauma, burns). Patho: stasis, ischemia.

⭐ Rokitansky-Aschoff sinuses (mucosal herniations into the muscular layer) are pathognomonic for chronic cholecystitis.

Duct Dilemmas - Stones Astray, Pipes Blocked

• Choledocholithiasis: Gallstones in Common Bile Duct (CBD).
  • Symptoms: RUQ pain, jaundice, ↑ALP, ↑GGT. MRCP confirms.
  • Complications: Acute pancreatitis, cholangitis.
• Acute Cholangitis: CBD obstruction + bacterial infection.
  • 📌 Charcot's triad: Fever, jaundice, RUQ pain.
  • 📌 Reynold's pentad: Charcot's + hypotension, altered mental status (severe).
  • Organisms: E. coli, Klebsiella, Enterococcus.
  • Tx: IV Abx, urgent biliary drainage (ERCP).

  ⭐ Most common cause of ascending cholangitis is choledocholithiasis with biliary obstruction.

• Mirizzi Syndrome: CHD compression by impacted cystic duct/GB neck stone.
  • Type I: External compression.
  • Type II-IV: Cholecystocholedochal fistula.
• Biliary Strictures: Bile duct narrowing.
  • Causes: Post-surgical (iatrogenic), PSC, malignancy, chronic pancreatitis.
  • Symptoms: Jaundice, pruritus, recurrent cholangitis.

Biliary Neoplasms & Oddities - Growth & Glitches

• Gallbladder Carcinoma (GBC):
  • Adenocarcinoma; most common biliary cancer.
  • Risks: Gallstones (porcelain gallbladder), chronic cholecystitis, S. typhi, choledochal cysts.
  • Late symptoms, poor prognosis.
• Cholangiocarcinoma (CCA):
  • Bile duct malignancy: intrahepatic, perihilar (Klatskin), distal.
  • Risks: PSC, liver flukes (Clonorchis, Opisthorchis), choledochal cysts, Caroli's.
  • Markers: ↑CA19-9, ↑CEA.

  ⭐ Klatskin tumor: hilar CCA at hepatic duct bifurcation.

• Biliary Atresia:
  • Neonatal obstructive cholangiopathy; fibrosis of extrahepatic ducts.
  • Jaundice, acholic stools by 2 months.
  • Kasai procedure; transplant common.
• Choledochal Cysts:
  • Congenital biliary dilations (Todani types).
  • Risks: Pancreatitis, cholangitis, ↑CCA. Excision.
• Caroli's Disease:
  • Congenital intrahepatic duct dilation; with ARPKD.
  • Risks: Stones, cholangitis, ↑CCA.

High‑Yield Points - ⚡ Biggest Takeaways

• Cholesterol gallstones (common, Four Fs); Pigment stones: hemolysis (black), infection (brown).
• Acute cholecystitis: cystic duct stone obstruction, positive Murphy's sign.
• Chronic cholecystitis: Rokitansky-Aschoff sinuses; porcelain gallbladder (↑ cancer risk).
• Ascending cholangitis: Charcot's triad (fever, jaundice, RUQ pain); Reynolds' pentad adds shock, confusion.
• PSC: linked to ulcerative colitis, p-ANCA, "onion-skin" fibrosis; ↑ cholangiocarcinoma risk.
• Gallbladder carcinoma: adenocarcinoma; risks: gallstones, porcelain gallbladder. Klatskin tumor: hilar cholangiocarcinoma.