Rare Case of Pediatric Disseminated Choroid Plexus Papilloma: Literature Review and Call for Reclassification

Introduction: Choroid plexus tumors are rare neuroectodermal tumors that arise from the choroid plexus. Choroid plexus papillomas (CPPs) represent the lowest grade of these types of tumors and have a WHO grade I designation. Despite their typical low grade, some CPPs can exhibit aggressive behaviors including parenchymal invasion and dissemination throughout the neuro-axis. Due to their association with the choroid plexus, patients with CPP commonly present with signs and symptoms of hydrocephalus and increased intracranial pressure. Case Presentation: A 2-year-old male presented in extremis with acute hydrocephalus and seizure. He was found to have a large left intraventricular mass with innumerable intraparenchymal and extra-axial cysts throughout his neuro-axis. A literature review revealed five similar disseminated CPP cases with innumerable lesions. This is the youngest reported patient with disseminated CPP and the first with multiple compressive lesions. Following cranial resection and thoracic decompression, the patient's lesions have remained stable (2 years of follow-up). A literature search of the PubMed/Medline databases was performed using the search terms ["disseminated choroid plexus papilloma"OR "choroid plexus papilloma"OR "metastatic choroid plexus papilloma"] up to March 2021. Articles were then screened for similar patient radiographic presentation and histological diagnosis. To mitigate publication bias, referenced articles were utilized to identify other case reports and case series. Discussion/Conclusion: We describe a rare case of a lateral ventricle CPP with widespread leptomeningeal dissemination causing acute obstructive hydrocephalus and compressive myelopathy requiring cerebrospinal fluid diversion and intracranial resection followed by thoracic spine decompression. This case report serves to broaden knowledge of disseminated CPP and to encourage complete neuro-axis imaging for choroid plexus tumors. Additionally, we propose a naming paradigm refinement that includes radiographic characteristics.