Abstract
We investigated preoperative imaging of pyloric-type adenoma and carcinoma in adenoma of the gallbladder, comparing their microscopic findings in 13 patients. Thirteen lesions were divided into Group H (pyloric-gland adenoma with high-grade dysplasia, 8 lesions) and Group L (that with low-grade dysplasia, 5 lesions) histologically. By EUS, the lesions were detected as polyps with a thin stalk and nodular or smooth surfaces and often showed a homogeneous pattern (Group H: 7/7, Group L: 1/3) and small cystic spots (Group H: 5/7, Group L: 2/3) inside. Contrast enhanced CT showed enhancement effect on the polyp (Group H: 6/6, Group L: 3/3). High b-value diffusion-weighted MRI for the lesions showed no positive signal (Group H: 0/4, Group L: 0/2) and showed no significant difference between the apparent diffusion coefficient (ADC) values in the two groups (Group H: 2.87±0.39×10-3 mm2/s, Group L 2.94±0.028×10-3 mm2/s) (p=0.75). The homogeneous pattern and cystic spots shown by EUS histologically corresponded to the dense glands and cysticly dilated glands, respectively. These findings indicate that it is difficult to differentiate Group H and Group L by preoperative imaging.
