Ventricular Meningiomas: Surgical Strategies and a New Finding That Suggest an Origin From the Choroid Plexus Epithelium

Abstract

The aim of this study is to share our experiences on a series of 21 patients with intraventricular meningiomas (IVMs). Histopathologic examinations are reviewed in detail and the cell of origin of IVMs is discussed. We retrospectively reviewed 1372 patients with intracranial meningioma who were surgically treated between September 1986 and July 2018. From this cohort, 21 patients with IVM were identified. The clinical, radiologic, surgical, and follow-up records were analyzed. The archival pathologic specimens were reviewed. Tissue microarray blocks were performed from the formalin-fixed, paraffin-embedded samples of all IVM cases, 2 choroid plexus tissue adjacent to the tumors, and 10 extraventricular fibrous meningioma cases selected as control randomly. Immunohistochemical staining with the antibodies S-100, SOX10, NGFR, and OTX2 was performed according to the protocols indicated by the manufacturers. Surgical complications included hemiparesis in 1 patient (5%), postoperative seizure in 1 patient (5%), sensorial aphasia in 1 patient (5%), and preexisting headache in 1 patient (5%). Seventeen (81%) of the IVMs had grade I pathology and 4 (19%) had grade II pathology. The immunoprofile of IVMs is identical to the immunoprofile of normal choroid plexus epithelium. Transcortical approaches using intraoperative ultrasonography and intraoperative monitoring with avoidance of eloquent cortical areas can achieve good outcomes. Resection of the choroidal attachments should be attempted. Our results indicate that IVMs do not show arachnoid cap cell phenotype and the findings support that IVMs originate from the choroid plexus epithelium or the progenitors of the choroid plexus epithelium.