Cerebral infarction due to a spontaneous tumor embolus from lung cancer.

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