[A diffuse metastatic leptomeningeal carcinomatosis from gallbladder cancer; case report].

We encountered a 72-year-old woman with diffuse metastatic leptomeningeal carcinomatosis, who first suffered from occipital pain and died about a month after onset. On postmortem examination, gallbladder cancer (adenocarcinoma) was found to be the primary disease. We focused on its frequency and the metastatic route. On the metastatic route, we obtained the following results: tumor cells infiltrated only the cerebrospinal fluid, but not the areas surrounding the gallbladder cancer (spine or spinal cord) or into the brain parenchyma. A comparative study of the state of cerebrospinal fluid between the ventricle and the subarachnoid space disclosed that the cerebrospinal fluid pressure, cell count, and CEA and CA 19-9 levels increased more in the intraventricular cerebrospinal fluid, especially when the CEA level was higher than that in the serum. On histopathological examination, tumor emboli were seen in choroidal vessels in the ventricular wall, and tumor cells existed sparsely around choroidal secretory vessels. These results were thought to support the theory of hematogenous metastasis as Little et al proposed.