Ruptured distal middle cerebral artery aneurysm in a pediatric patient: illustrative case.

backgroundPediatric intracranial aneurysms (IAs) are rare, with an estimated occurrence of less than 5% of all IAs. The pathology of pediatric aneurysms may differ from adult IAs and require additional workup. Management options for pediatric aneurysms include both endovascular and open procedures. The authors report the case of a 7-year-old male with a large, partially thrombosed distal middle cerebral artery (MCA) aneurysm. OBSERVATIONS: The patient presented with left hemiparesis. The initial CT imaging showed an intraparenchymal hemorrhage (IPH) in the right frontal lobe. Digital subtraction angiography (DSA) showed a large, partially thrombosed distal MCA aneurysm. A right frontal craniotomy was performed for aneurysm clipping, excision, and hematoma evacuation. Intraoperative DSA was utilized to confirm the absence of residual aneurysm. At the 6-month follow-up appointment, the patient had returned to his neurological baseline. He continues annual cerebrovascular radiographic surveillance. LESSONS: Pediatric aneurysms presenting with IPH are exceedingly rare. In this patient, an open surgical intervention was favored due to the presence of an IPH and the distal location of the aneurysm. Pediatric aneurysms may have a different etiology than that of adults. Because of this difference, these lesions require special considerations with regard to workup and treatment. https://thejns.org/doi/10.3171/CASE24373.