Courvoisier's Law

The Physiological Basis

• In choledocholithiasis (gallstones), the obstruction develops in the setting of chronic calculous cholecystitis. Years of inflammation cause the gallbladder wall to become fibrotic and scarred — it cannot distend, so it remains impalpable even when the CBD is obstructed.
• In malignant obstruction (e.g., pancreatic head cancer), the biliary tree is compressed by a gradually growing tumor. The gallbladder wall is normal and compliant, so bile accumulates and the gallbladder distends and becomes palpable.

"The absence of a palpable gallbladder in most patients with biliary obstruction from duct stones is the basis for Courvoisier's law, that is, that the presence of a palpably enlarged gallbladder suggests that the biliary obstruction is secondary to an underlying malignancy rather than to calculous disease." — Harrison's Principles of Internal Medicine, 22E

Classic Presentation

Important Caveats

1. Not an absolute rule — Courvoisier himself acknowledged exceptions. A palpable gallbladder can occasionally occur with stones, and malignant obstruction doesn't always produce a palpable gallbladder.
2. Serum bilirubin clue: Levels ≥342 μmol/L (≥20 mg/dL) strongly favor neoplastic obstruction over stones (stones rarely push bilirubin that high).
3. Sensitivity is low — the Courvoisier sign (palpable gallbladder) is actually uncommon on examination even in malignant obstruction, so its absence does not rule out malignancy.
4. A scarred/contracted gallbladder from prior cholecystitis can never distend — so even malignant obstruction may not produce the sign in that setting.

Named After