Multiple fungal aneurysms: report of a rare case implicating steroid as predisposing factor

A 61-year-old man with a ruptured aneurysm of the anterior communicating artery developed hemorrhagic cerebral infarction 22 days after an operation associated with occlusion of the right angular artery. Angiograms further revealed sequential changes of intracranial vessels including progressive obstructions of the right anterior and middle cerebral arteries and four aneurysms on the left pericallosal artery. Subsequently, the patient became comatose and died. At autopsy the newly formed aneurysms originating from the left pericallosal artery were of fungal (Phycomycetes) origin and numerous nonseptate, branching hyphae were also seen in the obstructed cerebral arteries. Intracranial fungal aneurysms are reviewed in the literature and the pathogenesis in the present case is discussed.