起源于中枢神经系统外部的颅内转移瘤据报道发病率约为18%～35%,大多数是经颅内血管瘤栓播散在脑实质内,呈单发或多发的孤立肿物;经颈外动脉分支播散于颅顶及脑膜者少见。癌细胞可经脉络丛或癌肿靠近皮质表面而播散到软脑膜。癌性脑膜病占全身癌肿尸检的8%,而全身癌肿播散到硬脑膜或硬膜下腔者罕见,而由于硬膜浸润并发硬膜下血肿则尤为罕见(据文献记载不足60 Intracranial metastases, which originate outside the central nervous system, have been reported to be present at about 18% to 35% of the incidence, most of which are isolated solitary or multiple solitary masses disseminated intracranial hemangiomas in the parenchyma of the brain. External carotid branch disseminated in the skull and meninges are rare. Cancer cells may spread to the pia mater through the choroid plexus or cancer near the cortical surface. Cancerous meningitis accounts for 8% of all autopsy cancers of the body, whereas systemic cancers are uncommon in the dura or subdural space, and are rarer due to subdural hematoma (less than 60 documented)