Thrombosed Pediatric Cerebral Arteriovenous Malformation Mimicking an Intraventricular Tumor: A Case Report

Thrombosed cerebral arteriovenous malformations (AVMs) are rare entities in the pediatric population and may present significant diagnostic challenges. Thrombosis can alter the typical vascular imaging features of these lesions, leading to a loss of flow-related signs and causing them to mimic intracranial neoplasms. We report the case of a 13-year-old boy who presented with a first-onset generalized seizure and was found to have a large intraventricular mass initially suspected to be a tumor based on neuroimaging findings. Magnetic resonance imaging demonstrated a bilobed intraventricular lesion with heterogeneous signal intensity, minimal contrast enhancement, absence of flow voids, and small cystic degenerative areas. Given the diagnostic uncertainty and the presence of focal neurological deficits, microsurgical resection was performed. Histopathological examination revealed a thrombosed AVM without neoplastic features. This case highlights the importance of considering thrombosed AVMs in the differential diagnosis of intraventricular masses in children, even in the absence of classic vascular imaging characteristics.