A cerebral infarction of the left occipital lobe developed in a 65-yea
r-old man with squamous cell carcinoma of the right lung. Neurological
examinations and brain CT showed findings typical of ordinary infarct
ion. Postmortem examination revealed a tumor embolus within the poster
ior cerebral artery. Such spontaneous tumor emboli large enough to obs
truct a larger-sized artery are rare.