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

Outcomes after gamma knife radiosurgery for intraventricular meningiomas

BACKGROUND

Intraventricular meningiomas (IVMs) are rare tumors with considerable treatment-associated morbidity due to their challenging location. Treatment with stereotactic radiosurgery (SRS) is sparsely reported in the literature. We describe our experience over the last 35 years using Gamma knife radiosurgery (GKRS) for IVMs.

METHODS

We retrospectively reviewed the GKRS database identifying 2501 meningiomas treated at the University of Pittsburgh Medical Center over the last 35 years. Nineteen patients with (12 males, mean age = 53.2 years, range 14-84) 20 IVMs were identified. Headache was the most frequent presenting symptom (N = 12), and the trigone of the lateral ventricle was the most common location (N = 18). The median tumor volume was 4.8 cc (range, 0.8-17). The median margin dose was 14 Gy (range, 12-25) delivered at 50% isodose line.

RESULTS

At a median follow-up of 63.1 months (range, 6-322.4) symptom control was achieved in 18 (94.7%) patients. The overall progression-free survival (PFS) was 95% at 5 years, and 85% at 10-years. After Log-rank test, patients who underwent GKRS within 12 months after diagnosis (vs. ≥ 12 months, X²: 4.455, p = 0.035), patients treated with primary GKRS without prior biopsy (vs. prior biopsy, X²: 4.000, p = 0.046), and patients with WHO grade I meningioma (vs. WHO II, X²: 9.000, p = 0.003) had a longer PFS. Imaging showed peritumoral edema in seven cases at a median of 10.5 (range, 6.13-24.3) months after GKRS. Only three of these patients were symptomatic and were successfully managed with oral medications. Cox´s regression revealed that a V12Gy ≥ 10 cc [HR: 10.09 (95% CI: 2.11-48.21), p = 0.004], and tumor volume ≥ 8 cc [HR: 5.87 (95% CI: 1.28-26.97), p = 0.023] were associated with a higher risk of peritumoral edema.

CONCLUSION

GKRS is an effective and safe management option for intraventricular meningiomas. Early GKRS should be considered as a primary management modality for small and medium sized IVM and adjuvant management for residual IVMs.

Risk Factors of Postoperative Meningitis in Lateral Ventricular Trigone Meningiomas: A Clinical Analysis of 64 Patients

Purpose

Patients with intraventricular tumors are more susceptible to postoperative meningitis (POM) than other intracranial tumors. In this study, we explored the risk factors of POM in lateral ventricular trigone meningiomas (LVTMs).

Methods

Clinical features of 64 patients with LVTMs were analyzed. Age, gender, body mass index, medical history, intraoperative blood loss (IBL), intraventricular drainage placement, surgical duration, tumor grade, postoperative tumor cavity hemorrhage, and tumor size were included in univariate and multivariate analyses of POM.

Results

Of the 64 patients, 14 patients (21.9%) received diagnosis of POM. The univariate analysis revealed IBL ≥400 mL (odds ratio [OR], 9.012; p = 0.003), tumor size ≥50 cm³ (OR, 3.071; p = 0.080), and surgical duration ≥5 h (OR, 2.970; p = 0.085) were considered possible risk factors for POM (p < 0.10). Tumor size (R = 0.514) and surgical duration (R = 0.624) were significantly correlated with IBL (p < 0.05). In the multivariate analysis, only IBL was found to be an independent risk factor for POM.

Conclusion

The IBL ≥400 mL is independently associated with the increased risk of POM in LVTM patients. Our results demonstrate the importance of controlling IBL for preventing POM, especially in large tumors and long surgeries.

Intraventricular Meningiomas: Clinical-Pathological and Genetic Features of a Monocentric Series

Intraventricular meningiomas (IVMs) are rare (0.5-5%) and usually low-grade (90% grade I) brain neoplasms. Their recurrence rate is lower than that of extra-axial meningiomas, but their surgical resection can be burdened with life-threatening complications, which represent the major cause of the reported 4% mortality. The aim of this study is to characterize the molecular portrait of IVMs to identify potential therapeutic targets. For this, we explored mutations and copy number variations (CNV) of 409 cancer-related genes and tumor mutational burden (TMB) of six cases, using next-generation sequencing. Five IVMs were grade I and one was grade II; none recurred, in spite of partial surgical resection in one case. NF2 mutation was the only recurring alteration and was present in three of the six IVMs, in association with SMARCB1 mutation in one case. None of the cases was hypermutated (TMB > 10 mutations/Mb). NF2-mutant progressing or recurring IVMs could potentially be treated with targeted therapies applied to other NF2-mutant tumors, as an alternative to surgery or radiosurgery, while in view of their low TMB they are unlikely candidates to immune check-point inhibition.

Meningioma Originating From Choroid Plexus of Foramen of Luschka: A Rare Case Report and Tip of Differential Diagnosis

Meningiomas are the most common benign brain tumors, and most of them originate from the dura mater. However, in some cases, they can originate from the choroid plexus, and they are rarely found in the posterior cranial fossa. A 63-year-old female patient presented with dizziness and swallowing difficulty and was found to have a homogeneously enhancing mass in the right posterior cranial fossa. Mass removal was performed through retrosigmoid suboccipital craniotomy, and the mass was confirmed to originate from the choroid plexus. The pathological diagnosis was meningothelial meningioma. The patient had temporary swallowing difficulty but recovered without any neurological sequelae. We report a rare case of a lower cerebellopontine angle meningioma without dural attachment originating from the choroid plexus of the foramen of Luschka.

Malignant intraventricular meningioma: literature review and case report

Malignant intraventricular meningiomas (IVMs) are very rare with only a few reported cases. A midline search up to December 2020 selected 40 articles for a total of 65 patients. The inclusion criteria were series and case reports in English language, as well as papers written in other languages, but with abstracts written in English. Malignant IVMs at the first diagnosis (group A, 50 patients) and those with anaplastic transformation from previous WHO grades I and II tumors (group B, 15 patients) were separately analyzed. The unique personal case among 1285 meningiomas (0.078%) is also added. Malignant IVMs mainly occur in women (61%) with a median age of 45 years and are mainly located in the lateral ventricle (93%) and trigonal region (74%), with no cases in the fourth ventricle. Irregular borders (80%), heterogeneous enhancement (83%), and perilesional edema (76%) are the most frequent radiological findings. The histology was mainly pure anaplastic (85%), whereas papillary (7%), rhabdoid (5%), and mixed forms (3%) are very rare. The CSF spread was found in 60% of the cases. The prognosis is very dismal, with an overall median survival of 17.5 months after surgery for the anaplastic forms. Malignant IVMs at initial diagnosis (group A) show better overall survival (25 months) than those occurring from anaplastic transformation of lower grade tumors (group B) (10.1 months).

Customising the surgical management for intraventricular meningiomas - 'one size doesn't fit all'

BACKGROUND

Intraventricular meningiomas are uncommon and gross total resection is the recommended treatment. However, total resection may not always be possible, especially in locations in which the lesions are adherent to veins and neural structures. We share our experience with intraventricular meningiomas, focusing on the management strategies and outcomes.

PATIENTS AND METHODS

We describe the data of 7 patients with intraventricular meningiomas operated at our institute over the last 9 years. Three patients had a third ventricular tumor of which two had lesions straddling across the foramen of Monro. The remaining 4 patients had trigonal mass. The clinico-radiological features, management strategies and outcomes have been elaborated with a mean follow-up of 57 months.

RESULTS

The common clinical presentations were raised intracranial pressure symptoms, visual field defects and memory deficits. One patient had multiple meningiomas. Total excision was achieved in all except in 2 patients in whom the lesion straddled across the foramen of Monro with dense adhesions to veins and neural structures. Staged resection was required in one patient with a large trigonal mass. All patients had a low-grade lesion. The tumor recurred in one patient (post-pregnancy) after partial resection. All the patients improved neurologically, and none had added deficits.

CONCLUSIONS

Gross total resection of intraventricular meningiomas although desirable may not be possible in certain cases in which the risks outweigh the benefits. These tumors often are of low histological grade and the treatment strategies should be individualized. Regular follow-up is warranted as these tumors may recur despite a low histological grade.