Routes of hepatic metastasis of gallbladder carcinoma

This clinicopathologic study aims to clarify routes of hepatic metastasis of gallbladder carcinoma. Nineteen liver specimens obtained by extensive hepatectomy performed for the treatment of advanced gallbladder carcinoma were analyzed. We defined hepatic metastasis as a discrete hepatic lesion separate from the primary tumor and paid special attention to portal tracts at the margins of direct hepatic invasion. Eleven early metastatic foci were demonstrated histologically in 6 cases, most commonly in segments adjacent to the gallbladder. All cases with hepatic metastasis had direct hepatic invasion. Nine of the 11 metastatic lesions were located within the portal tracts or accompanied by invasion into the portal tracts. Because they are in continuity with areas of direct hepatic invasion, the portal tracts at the invasive margin often were involved by cancer cells that spread along these tracts. These results suggest that the most important route in development of hepatic metastasis from gallbladder carcinoma is along the portal tracts after direct hepatic invasion.