Neoplastic cerebral aneurysm from lung cancer. Case report

A 56-year-old man with lung cancer developed a massive intracerebral hematoma resulting from rupture of a small neoplastic aneurysm in a cortical branch of the left posterior temporal artery. Histologically, undifferentiated squamous cells formed an embolus in the aneurysm and destroyed the aneurysm wall. No tumor mass was evident around the aneurysm.