A Case of Cerebral Tumor Embolism from Extracardiac Lung Cancer Treated by Mechanical Thrombectomy

Cerebral tumor embolism is a rare cause of acute ischemic stroke, and extracardiac carcinoma is an extremely rare cause. A 34-year-old man who had been diagnosed with lung cancer developed right hemiparesis and aphasia, with the National Institutes of Health Stroke Scale (NIHSS) score of 17. Magnetic resonance imaging (MRI) showed early ischemic change in the insular cortex and frontotemporal lobe and left internal carotid artery (ICA) terminal occlusion was confirmed by magnetic resonance angiogram (MRA). Mechanical thrombectomy (MT) with contact aspiration by a Penumbra ACE 68, followed by combined technique with a stent retriever was performed, and a soft, fragile embolus was retrieved. Finally, good recanalization was achieved (Thrombolysis in Cerebral Infarction [TICI] scale 2b), and on the next day, the right hemiparesis and aphasia were improved. However, the patient’s general condition gradually worsened, and 43 days after thrombectomy, he died from respiratory failure. The retrieved embolus was examined pathologically and diagnosed as mucoepidermoid carcinoma of the same type as his lung cancer. Chest computed tomography (CT) showed that tumor invaded the right pulmonary vein and left atrium; these findings suggested that a piece of the tumor in the left atrium flowed into the left ICA and caused the acute ischemic stroke.