Although central nervous system (CNS) metastases are common in advanced cancer, CNS involvement solely by intravascular tumor cells, known as intravascular carcinomatosis, is extremely rare. We report two cases of brain metastasis in which tumor cells were restricted to the vascular lumina without parenchymal involvement, resulting in ischemic lesions. The first patient is a previously healthy young woman who presented with symptoms of community-acquired pneumonia and progressed to respiratory failure. Computed tomography of the brain showed infarcts of differing ages. At autopsy, she was found to have widely metastatic cervical squamous cell carcinoma and cerebral tumor emboli with multifocal infarcts, mainly microinfarcts. The second patient is an elderly man with cognitive impairment and mild Parkinsonism who presented with symptoms of a urinary tract infection. Magnetic resonance imaging of the brain showed atrophy and changes suggestive of chronic microvascular ischemic disease. Postmortem examination demonstrated prostatic adenocarcinoma and cerebral tumor emboli with multifocal infarcts. These cases illustrate that this pattern of intracranial metastasis may rarely be a cause of cerebral ischemic lesions and emphasize the importance of thorough pathologic examination of the brain.

中文翻译：

---

脑血管内癌变：两例报道。

尽管中枢神经系统（CNS）转移在晚期癌症中很常见，但仅由血管内肿瘤细胞参与的CNS转移（称为血管内癌变）极为罕见。我们报告了脑转移的两个案例，其中肿瘤细胞被限制在无实质参与的血管腔内，导致缺血性病变。第一位患者是一位以前健康的年轻女性，她出现了社区获得性肺炎的症状，并发展为呼吸衰竭。脑部计算机断层扫描显示不同年龄的梗塞。尸检时发现她患有广泛转移的子宫颈鳞状细胞癌和脑肿瘤栓塞，多灶性梗塞，主要是微梗塞。第二名患者是患有认知障碍和轻度帕金森病的老人，其表现为尿路感染的症状。脑部磁共振成像显示萎缩和变化提示慢性微血管缺血性疾病。验尸显示前列腺癌和脑肿瘤栓塞伴多灶性梗塞。这些病例说明颅内转移的这种模式可能很少是脑缺血性病变的原因，并强调了对大脑进行彻底病理检查的重要性。