Uncommon presentation of pediatric ruptured intracranial aneurysm after radiotherapy for retinoblastoma. Case report.

OBJECTIVE

Radiation-induced intracranial aneurysms are a rare entity with high mortality. Their pathogenesis is still in debate. Their unique anatomy and behavior should be considered when deciding the proper management. A background of radiation, uncommon anatomic aspects, age of presentation, and location guide us to suspect a radiation-induced etiology. We report the case of a pediatric patient with a ruptured intracranial aneurysm, who previously received radiation therapy to the orbits. We aim to contribute to the literature of this uncommon condition and stress the importance of its prompt diagnosis and treatment.

METHODS

A 12-year-old boy, who received radiation therapy for recurrent bilateral retinoblastomas at age 4 months, suddenly developed severe headache associated with nausea and vomiting. A computed tomography scan revealed subarachnoid hemorrhage. A 4-vessel cerebral angiogram revealed a 2-mm aneurysm in the right A1 segment. The aneurysm was clipped successfully with excellent outcome. After 3 years of follow-up, the patient remains neurologically intact and asymptomatic. A new computed tomography angiogram revealed no new aneurysms.

CONCLUSIONS

Vascular abnormalities develop after radiation injury to the brain. Aneurysm formation after radiation therapy has been previously reported, probably secondary to endothelial injury. In this case, early presentation, unusual anatomy, location, and small size at rupture, in contrast with saccular aneurysms, suggest a radiation-induced etiology.