Delayed presentation of a pediatric giant traumatic pseudoaneurysm mimicking a brain tumor: a case report.

Intracranial pseudoaneurysms (IPAs) account for less than 1% of all intracranial aneurysms, yet they have been reported more frequently in the pediatric population, carrying a high risk of morbidity and mortality. Giant IPAs in children are extremely rare and may mimic intracranial tumors on imaging, making diagnosis challenging. Thrombosed pseudoaneurysms, in particular, can resemble neoplastic lesions due to their heterogeneous appearance and contrast enhancement patterns. This report describes the case of an 11-year-old boy with a history of head trauma five years earlier, who was admitted after developing a seizure following severe headache. Neuroimaging revealed a giant cystic-solid lesion in the frontal lobe, initially suspected to be a tumor. Surgery was planned, but intraoperatively the lesion was found to be vascular. Subsequent angiography demonstrated a giant pseudoaneurysm arising from the pericallosal branch of the right anterior cerebral artery. The patient was successfully treated with endovascular coil embolization. This case highlights that giant pseudoaneurysms can present years after head trauma in children and may radiologically mimic tumors. Careful preoperative imaging review and advanced vascular studies, when necessary, are essential for timely and accurate diagnosis. Additional reports in the literature will further improve our understanding of the clinical and radiological features of pediatric pseudoaneurysms and guide treatment selection.