Atypical cholesonograms in primary and secondary malignant disease of the biliary tract.

Hepatic metastases or mass lesion near the head of the pancreas are usually found when echograms are performed on patients with malignant diseases of the biliary tract. Atypical cholesonograms may result when the gall bladder itself is deformed or invaded by tumor, when tumor obstructing the bile duct is plaquelike and not detectable as a mass lesion, or when gall stones coexist as a purely incidental finding.