Delayed development of a de novo contralateral middle cerebral artery aneurysm in a patient with hyperimmunoglobulin E syndrome: A case report.

A 50-year-old female patient with hyperimmunoglobulin E syndrome (HIES) presented initially at the age of 48 years with subarachnoid hemorrhage (SAH) from a ruptured left middle cerebral artery (MCA) bifurcation aneurysm, which was treated successfully with coiling and microsurgical clipping. Angiography and cross-sectional imaging did not indicate evidence of any additional intracranial aneurysm. However, the patient presented two years later with SAH secondary to a new ruptured right MCA bifurcation aneurysm, which was treated successfully with microsurgical clipping. This case provides further evidence that HIES places the cerebral vasculature at increased risk for cerebral aneurysm formation and that special considerations are indicated in managing and monitoring these patients.