A palpable gallbladder with painless jaundice is unlikely to be due to stones
Mnemonic
“A palpable gallbladder with painless jaundice is unlikely to be gallstones.”
The logic is that chronic stone disease makes the gallbladder fibrotic and shrunken, so it cannot distend. A palpable, distended gallbladder therefore implies a different obstruction, typically carcinoma of the head of the pancreas or a cholangiocarcinoma.
The law is stated in the negative for a reason: it says what the cause is unlikely to be, not what it is.
Exceptions exist and are worth knowing: a double impaction (a stone in the cystic duct and another in the common bile duct), Mirizzi syndrome, an oriental cholangiohepatitis, and a stone forming in the common duct de novo.
Painless jaundice with weight loss is pancreatic cancer until proven otherwise, and it warrants urgent imaging regardless of whether the gallbladder is palpable.
Expansion
In the presence of painless obstructive jaundice, a palpable gallbladder is unlikely to be due to gallstones, malignancy should be suspected, most often carcinoma of the head of the pancreas or a cholangiocarcinoma.
The reasoning is anatomical. Longstanding stone disease causes chronic inflammation and fibrosis, producing a thick-walled, contracted gallbladder that cannot distend even when the bile duct is obstructed. A previously normal gallbladder obstructed by an external tumour distends freely.
Two important exceptions:
- Double pathology - a stone in the bile duct with a previously healthy gallbladder
- Mirizzi syndrome
The law works better in its positive than its negative form: a palpable gallbladder is meaningful, but its absence excludes nothing.