1Department of Surgery, Showa University Fujigaoka Hospital, 2The First Department of Pathology, Showa University
Layer structure of the gallbladder wall, Cholecystitis Gallbladder cancer, Ultrasonography
It is important to compare the layer structure in an ultrasonic image with histopathological findings of the gallbladder wall to diagnose the quality of hypertrophic lesions in the gallbladder wall and to understand the depth of gallbladder cancer. The layer structure in an ultrasonic image of the gallbladder wall generally falls into five categories: 1 layer/higher echo, 1 layer/comparable or lower echo, 2 layers, 3 layers, and 4 or morelayers. Of these, lesions which ultrasonographically show 1 layer/comparable or lower echo or a 2-layer structure and irregularity in the layer structure and in the inner surface of the gallbladder should be suspected of cancer. Histologically, some lesions of the abscess or granuloma type show an ultrasonic image similar to that of cancer, and require differentiation from cancer.
In the 3-layer structure of chronic cholecystitis, the second layer is considered to be related to fibrosis of the tunica propria muscularis and the connecting tunica subserosa, which is difficult to differentiate from cancer in evaluating the depth of cancer.