Background: Fungal or "true" mycotic aneurysms of the intracranial circulation are very rare. Rupture of a fungal aneurysm is fatal in almost 100% of cases.
Case description: We report a 65-year-old woman with a ruptured fungal aneurysm on the posterior communicating artery associated with occlusion of the internal carotid artery. She had a past history of gastric malignant lymphoma and subsequent granulocytopenia. She survived after surgical treatment including trapping of the aneurysm and a superficial temporal artery-to-middle cerebral artery bypass.
Conclusion: Improved immune response at the time of the onset of subarachnoid hemorrhage, as well as additional vasoreconstructive surgery, may have contributed to favorable outcome after surgical treatment.