Ultrasonography in carcinoma of the gallbladder.

Cholecystosonography in approximately 40,000 patients over five years in two university hospitals revealed 30 (75%) of the 40 macroscopic primary carcinomas. In 3 cases the carcinoma was obscured by gallstones with shadowing, in 3 cases the origin of a tumour mass was misinterpreted, and in 4 cases the neoplastic growth mimicked gallbladder inflammatory changes or sludge. Malignancy was incorrectly diagnosed or suggested in 25 patients. The most frequent cause of a false positive report was acute or chronic inflammation, found at surgery in 16 gallbladders. Four carcinomas of the pancreatic head were believed to be gallbladder tumours. Cirrhosis with marked gallbladder wall thickening, gastric carcinomas with metastases, a common duct carcinoma, and two cases of sludge (with normal control studies) caused a false suggestion of gallbladder carcinoma. The most frequent ultrasonographic finding in gallbladder carcinomas was a mass filling the gallbladder (15 diagnosed cases), followed by wall thickening (9 cases), and polypoid or fungating tumour (6 cases). Real-time ultrasonography is a useful method for the preoperative diagnosis of gallbladder carcinoma, but considerable diagnostic problems in the differentiation from inflammatory diseases may be encountered.