It's not the law

I agree that, because of the exceptions, Courvoisier's law¹ is not really a law. In the truest sense of the word, laws are rules created by the state or the courts, not medical observations. This particular observation has also been referred to as Courvoisier's sign² and Courvoisier's gallbladder,³ but none of the terms were coined by Courvoisier.

Over a century ago, in 1890, Courvoisier presented his observation that a palpable gallbladder in a patient with obstructive jaundice is often caused by a noncalculus abnormality of the hepatobilliary system (e.g., pancreatic cancer or stricture of the common bile duct). He qualified this observation by stating that “if further evidence of this can be found, this would be an important marker for differential diagnosis.”⁴ At what point the observation came to be referred to as a “law” is not clear, but it was acclaimed as such as early as 1905.⁵ More exceptions were noted later, which eventually led to skepticism about the “law,” although most studies that have examined its validity⁶ have confirmed the general trend of Courvoisier's observation. Chung³ observed that high-grade obstruction of the common bile duct over a prolonged period (which is likely with pancreatic carcinoma but can also occur with stones) is responsible for dilatation of the gallbladder in patients with obstructive jaundice, and this theory would explain the various exceptions to Courvoisier's gallbladder that have been noted in the literature. Verghese and Berk⁷ suggested that “Clarity might be restored to this murky field by changing the eponym to ‘Courvoisier’s gallbladder.'”

There is no consensus on the proper eponym for this observation, but this has become an academic exercise because technological advances and early interventions in patients with gallstones or jaundice mean that the problem is usually addressed before it reaches this stage.

Malvinder S. Parmar Medical Director (Internal Medicine) Timmins and District Hospital Timmins, Ont.