ENDOSCOPIC ULTRASONOGRAPHY OF THE GALLBLADDER COMPARED WITH PATHOLOGICAL FINDINGS

Abstract

The endoscopic ultrasonography (referred to as "EUS" hereafter) was employed in the diagnosis of gallbladder diseases in order to overcome diagnostic limitations of the conventional ultrasonography.
Eighteen normal cases in autopsy and 90 clinical cases with gallbladder diseases underwent EUS. The instrument used in this study was the third prototype EUS with a 7.5 MHz trnasducer (Olympus GF-UM1).
The gallbladder wall was demonstrated by EUS as 3 layers in the clinical examinations as well as in the normal autopsy specimen in water-bath. The comparison between findings by EUS and by histology made it possible to reveal the kind of tissue components to be matched with these ultrasonography layers.
The 1st and most inner layer with slightly high echoic level meant the mucosal layer, the 2nd thin layer with low echoic one implicated the muscular layer and the 3rd high echoic layer was supposed to represent the subserosal and serosal layer.
The gallbladder wall in case of adenomyomatosis came into sight as 2 layers consisting of a low echoic and thick layer and another high echoic layer. And the small cystic echoes were visualized in the inner low echoic layer by EUS.
Concerning protruded lesions of the gallbladder, EUS enabled us to have a clear view of the cholesterol polyps in the gallbladder as a multiple granular structure composed of high echoic spots.
EUS, also, made it possible to disclose the polypoid type of gallbladder cancer as the papillary irregular low echoic mass. The tumor infiltration into the gallbladder wall was clearly demonstrated by EUS as the destruction of 3 layers of the gallbladder wall. This appearance also might help differentiate cancer from the other benign polypoid lesions.