Diffuse idiopathic intracranial fusiform aneurysm development. Case report and literature review.

Background: Fusiform intracranial aneurysms (FIAs) are uncommon lesions representing less than 15% of all intracranial aneurysms in most large series. Their etiology has been linked to a variety of causes including atherosclerosis, fibromuscular dysplasia, cystic medial necrosis, connective tissue disease, hypertension, diabetes, hyperlipidemia, infection, cardiac myxoma, oral contraceptive use, vasculitis, and lymphoproliferative disorders. The finding of numerous lesions in a single patient is distinctly uncommon.

Case Description: We describe the unique case of a 47-year-old female who developed multiple FIAs over a 6-year period without an obvious underlying pathology. The patient's medical history was significant for obesity, migraine headaches, insomnia, breast cancer, and chronic skin rash. Various diagnoses were explored including infectious etiologies, autoimmune vasculopathies, malignancy-related causes, connective tissue disorders, and underlying genetic conditions. However, all investigations, including aneurysm wall and skin biopsies were negative or deemed noncontributory toward making a definitive diagnosis.

Conclusion: We report an unusual case of a patient with a normal cerebral angiogram developing numerous, FIAs without obvious underlying etiology over a 6-year period. Close clinical and radiological follow-up is recommended in this case because the natural history of the disease is unclear at this point. The literature regarding potential causes of multiple fusiform intracranial aneuryms is reviewed.