A case of metastatic brain tumor causing multifocal cerebral embolism.

The patient was a 72-year-old woman who had previously undergone treatment for femoral chondrosarcoma (histologically rated as myxofibrosarcoma). She suddenly developed left homonymous hemianopsia and was diagnosed with cerebral embolism. Because she had atrial fibrillation, we treated her for cardiogenic cerebral embolism. About 3 months later, however, she developed left hemiplegia, and head magnetic resonance imaging revealed multiple tumorous lesions affecting the previously detected infracted area and several new areas. We assumed that a tumor embolus had caused cerebral embolism, which resulted in growth of the tumor from the embolus and formation of a metastatic brain tumor. The metastatic foci formed from the tumor embolus were visualized by diagnostic imaging, and histological examination of the resected tumor confirmed that the brain tumor had occluded the brain vessel (tumorigenic cerebral embolism). No such case has been reported to date, and this case seems to be important.