Cystic meningioangiomatosis in neurofibromatosis type 2: an MRI–pathological study

Death in a bathtub of an adolescent with neurofibromatosis type 2 exhibiting meningioangiomatosis with white matter involvement

Neurofibromatosis type 2 (NF2) is a neurocutaneous syndrome characterized by the development of multiple benign tumors, including vestibular schwannomas and meningiomas, in the nervous system. Seizures are rarely associated with NF2, and the lethality of this condition typically stems from tumor growth and related complications, leaving the incidence of sudden death largely unreported. This report discribes a 16-year-old girl with a history of NF2 and occasional seizures who died unexpectedly in a bathtub. Postmortem examination revealed multiple tumors in the cranial nerves (schwannoma), under the dura mater (meningioma), and in the upper cervical cord (neurofibroma). Typical signs of drowning, such as foam in the airways, were not present. Upon histological examination, meningioangiomatosis (MA) was observed in the cerebellum and the cerebral cortex, specifically in the frontal lobe, temporal lobe, and insula. The MA extended into the white matter, exhibiting severe perivascular fibrosis and cystic dilatation of perivascular spaces in the frontal lobe and cerebellum. Additionally, glial microhamartomas were detected both around and separate from the MA. These autopsy findings suggest that sudden unexpected death in epilepsy (SUDEP) was the cause of death rather than drowning. Moreover, while NF2-associated MA is typically asymptomatic, unlike sporadic MA, which commonly presents with seizures, the spread of MA into the white matter is unusual in an NF2 patient. Therefore, MA with the white matter involvement could have been a factor causing the seizures and the occurrence of SUDEP in this NF2 patient.

A comprehensive histomolecular characterization of meningioangiomatosis: Further evidence for a precursor neoplastic lesion

Meningioangiomatosis (MAM) remains a poorly understood lesion responsible for epileptic disease. In the past, MAM was primarily described in the context of neurofibromatosis type 2 before being mainly reported sporadically. Moreover, the malformative or tumoral nature is still debated. Because a subset of MAM are associated with meningiomas, some authors argue that MAM corresponds to an infiltration pattern of these tumors. For these reasons, MAM has not been added to the World Health Organization (WHO) Classification of Central Nervous System Tumors as a specific entity. In the present study, we characterized a series of pure MAM (n = 7) and MAM associated with meningiomas (n = 4) using histopathology, immunohistochemistry, genetic (fluorescent in situ and DNA sequencing analyses), and epigenetic (DNA-methylation profiling) data. We evidenced two distinct morphological patterns: MAM with a fibroblastic-like pattern having few lesional cells, and MAM with a more cellular pattern. A subset was associated with the genetic alterations previously reported in meningiomas (such as a KMT2C mutation and a hemizygous deletion of chromosome 22q including the NF2 gene). The DNA-methylation profile, using a t-distributed stochastic neighbor embedding analysis, evidenced that MAM (pure or associated with meningiomas) clustered in a separate group from pediatric meningiomas. The present results seem to suggest that MAM represents a neoplastic lesion and encourage the further study of similar additional series so that it may be included in a future WHO classification.

Cystic meningioangiomatosis and cerebellar ependymoma in a child with neurofibromatosis type 2

We report a case of multifocal cystic meningioangiomatosis (MA), an exceptionally uncommon diagnosis even in patients with type 2 neurofibromatosis (NF2). A 2-year-old male with personal as well as family history of genetically-confirmed NF2 presented with incidental findings of MA after imaging for closed-head injury. Computed tomography and magnetic resonance imaging revealed multifocal subcortical and basal ganglia cysts, enhancing tumor-like vascular encasement, and a cerebellar ependymoma with atypical features. Given the paucity of available literature describing this pathology, imaging findings are discussed to further characterize this elusive disease. Radiologists must keep in mind that children with NF2 may not only present with MA, but also a constellation of MA with classic NF tumors, including ependymoma as in this case.

Variations and natural history of primary intraparenchymal lesions associated with neurofibromatosis type 2

The study aimed to investigate the clinical implications and natural history of primary intraparenchymal lesions in patients with neurofibromatosis type 2. Radiological findings of 15 neurofibromatosis type 2 cases were retrospectively collected. Twenty-seven primary intraparenchymal lesions were observed in 7 out of 15 patients (47%). Cortical/subcortical T2 hyperintense lesions and enlarged Virchow-Robin spaces were the most common findings in five and four patients, respectively. During the follow-up period (median 84 months), one new primary intraparenchymal lesion was identified and increased lesions were observed in two cases on contrast-enhanced MRI. Surgical resection was performed in one case pathologically diagnosed with atypical meningioma. Twenty-five other lesions without contrast enhancement presented no apparent growth during follow-up. Although most primary intraparenchymal lesions are benign, a subset of cases would present newly developed or increased lesions on contrast-enhanced MRI. Careful monitoring is necessary for such cases, and pathological confirmation should be considered.

Meningioangiomatosis: Multimodal Analysis and Insights From a Systematic Review

BACKGROUND

Meningioangiomatosis is a poorly studied, rare, benign, and epileptogenic brain lesion.

OBJECTIVE

To demonstrate that surgical resection and a short-time interval to surgery improves epileptic seizure control, we performed a systematic review and meta-analysis of meningioangiomatosis cases.

METHODS

Using PRISMA-IPD guidelines, the authors performed a systematic review and meta-analysis of histopathologically-proven meningioangiomatosis cases. Literature search in French and English languages (PubMed, Embase, the Cochrane Library, and the Science Citation Index) including all studies (January 1981 to June 2020) dealing with histopathologically-proven meningioangiomatosis, without age restriction. We assessed clinical, imaging, histomolecular, management, and outcome findings of patients with meningioangiomatosis.

RESULTS

Two-hundred and seven cases of meningioangiomatosis from 78 studies were included. Most meningioangiomatosis was sporadic, preferentially concerned male patients, younger than 20 years old, and allowed a functionally independent status. Epileptic seizure was the main symptom, with 81.4% of patients having uncontrolled seizures at the time of surgery. Meningioangiomatosis mainly had frontal (32.3%) or temporal (30.7%) locations. Imaging presentation was heterogeneous, and the diagnosis was often missed preoperatively. The histopathologic pattern was similar whatever the clinical presentation, and immunohistochemistry had limited diagnostic value. On molecular analysis, allelic loss at 22q12 was more frequent in samples of meningioangiomatosis-associated meningioma (37.5%) than in isolated meningioangiomatosis (23.1%). Time interval from diagnosis to surgery (p = 0.011) and lack of surgical resection of the meningioangiomatosis (p = 0.009) were independent predictors of postoperative seizure control.

CONCLUSIONS

Owing to low scientific evidence, a multicentric prospective study should help refining the management of meningioangiomatosis.

Sporadic Meningioangiomatosis Presenting as a Middle Cranial Fossa Arachnoid Cyst

BACKGROUND

Meningioangiomatosis is an extremely rare meningovascular disease of the central nervous system that is characterized by the proliferation of leptomeninges, cortical vessels, and perivascular spindled cells. Although it is a benign, neoplastic disorder that carries a good prognosis after surgical excision, initial diagnosis may be challenging as radiologic findings are often variable and nonspecific.

CASE DESCRIPTION

In this report, we describe an unusual presentation of meningioangiomatosis presenting as a symptomatic middle cranial fossa arachnoid cyst.

CONCLUSIONS

In view of the unexpected diagnosis and infrequency of this condition, the case is discussed in collaboration with current literature and management strategies.

Meningioangiomatosis: A review of the variable manifestations and complex pathophysiology

Meningioangiomatosis (MA) is a rare, complex and heterogeneous disease of meningovascular proliferation that is found primarily in the leptomeninges and cerebral cortex but can involve subcortical white matter and other brain regions such as the cerebellum and deep gray matter. MA may be found in pediatric or adult populations and may be sporadic or neurofibromatosis-associated. The presentation of MA is highly variable: it may be associated with other neurological diseases; clinically presents on a spectrum from asymptomatic to seizures or focal deficits; radiologically presents with multifocal, tumor-like, or cystic lesions, or may appear normal; and pathologically may have cellular or vascular predominance. In this article, we review the various manifestations of MA including neurofibromatosis-associated MA, multifocal MA, cystic MA, and MA associated with meningioma, other brain tumors, focal cortical dysplasia, neurodegenerative changes, and post-radiation changes. The treatment of MA is also reviewed. While the pathogenesis of MA remains elusive, we discuss the proposed theories such as developmental, dysplastic, hamartomatous or reactive ethology in given variants. It is important for physicians to be aware of MA as more research on this complex entity is needed and timely diagnosis may benefit outcomes in patients with MA.

Growing Cyst-Like White Matter Lesions in Children With Neurofibromatosis Type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease with prominent neurocutaneous manifestations. The most common intracranial imaging finding of NF1 on brain magnetic resonance imaging (MRI) is the high-signal intensity foci without a mass effect or growth in size.

PATIENT DESCRIPTION

We describe two children with NF1 in whom brain MRI showed growing cystic lesions and adjacent white matter signal abnormalities, which were confirmed as non-neoplastic cystic degeneration and reactive gliosis.

CONCLUSION

Growing cyst-like white matter lesions can be seen on serial brain MRI in children with NF1. Reactive gliosis with cystic degeneration could be a pathogenic basis of these cystic lesions.

Three cases of sporadic meningioangiomatosis with different imaging appearances: case report and review of the literature

Background

Meningioangiomatosis (MA) is a rare meningiovascular malformation or hamartomatous lesion in the central nervous system. Radiographic findings of MA may show a variety of characteristics according to different histological components. We present three cases of sporadic MA with different imaging appearances in an attempt to identify specific imaging characteristics.

Case presentation

In case 1, an irregular hyperdense solid mass was localized in the left middle cranial fossa, demonstrating low and equal signal intensity on T1-weighted imaging (T1WI; TR/TE 2,048.9 ms/26.1 ms), high signal intensity with multiple flow void effect on T2-weighted imaging (T2WI; TR/TE 4,000 ms/106.4 ms), and significant and homogeneous enhancement on post-contrast magnetic resonance imaging (MRI). In case 2, the lesion in the right insular lobe showed a cystic-mural nodule pattern. The cystic content demonstrated similar density or signal intensity as cerebrospinal fluid, while the mural nodule demonstrated equal density or signal intensity on computed tomography (CT) and MRI. On post-contrast MRI, the mural nodule showed significant enhancement, but the cystic wall and content showed no enhancement. In case 3, a remarkably enhanced solid nodule was found in the cortex of the left parietal lobe with multiple small cysts surrounding it. This nodule showed low signal intensity on T2WI and diffusion-weighted imaging (DWI; TR/TE 6,000 ms/96.8 ms, b = 1,000 s/mm²). The preoperative diagnoses of the above three cases were meningioma, hemangioblastoma, and ganglioglioma. However, all were pathologically diagnosed as MA.

Conclusion

The presented cases demonstrate that MA may present with solid and cystic imaging patterns, which may include large cystic-mural nodules and small intra- and extra-cystic patterns. Although MA imaging diagnoses are difficult, several MRI signs may include specific characteristics, such as a flow void effect on T2WI and separating cysts in the cystic MA (as shown in our cases), gyriform hyperintensity on T2-fluid attenuated inversion recovery (FLAIR) sequence, and susceptibility artifacts on T2 gradient echo (GRE) sequences (as found in the literature).

Multicystic meningioangiomatosis

Background

Meningioangiomatosis (MA) is a rare hamartomatous lesion. Only six cases of cystic MA have been reported in the literature.

Case presentation

We present a case of multicystic MA. A 21-year-old woman without any stigmata of neurofibromatosis type 2 presented with intractable seizures since 10 years. Brain magnetic resonance imaging revealed a well-defined, multicystic mass with heterogeneous signal intensity in the right temporal lobe. The patient underwent resection of the lesion and of the epileptogenic cortex under intraoperative electrocorticography (ECoG) assistance. Histopathological examination showed proliferation of perivascular cells that were arranged in a cuff pattern and were positive for vimentin, D2-40 and smooth muscle actin. Mutiple microcysts and enlarged perivascular spaces were present, which was similar to the structure of the arachnoid cavity. Hyalinized collagen fibers with round concentric acellular eosinophilic lamellae within areas of reactive gliosis were noted for the first time in MA. The patient was followed up without any clinical symptoms or recurrence for 2 years.

Conclusion

MA may originate from arachnoid and vascular tissue trapped in the cortical parenchyma during brain development, and the cysts may have resulted from the gradual accumulation of cerebrospinal fluid in the perivascular spaces of the trapped tissue. Resection of the lesion and of the epileptogenic cortex is important not only for pathological diagnosis but also for seizure control, and intraoperative ECoG assistance is recommended.

Incidental parenchymal magnetic resonance imaging findings in the brains of patients with neurofibromatosis type 2

PURPOSE

Whereas T2 hyperintensities known as NF-associated bright spots are well described in patients with neurofibromatosis type I (NF-1), there is a paucity of data on incidental findings in patients with neurofibromatosis type II (NF-2). We aim to characterize unexplained imaging findings in the brains of patients with NF-2.

MATERIALS AND METHODS

This study is retrospective, HIPAA-compliant and approved by the institutional review board. 34 patients with NF-2 underwent brain magnetic resonance imaging (MRI) between January 2000 and December 2012. T2 and T1-weighted imaging characteristics, diffusion weighted imaging (DWI) characteristics, and enhancement patterns were analyzed by visual inspection. Clinical information at time of imaging was available for all patients. Neuropathologic data was available for one patient.

RESULTS

We found unexplained T2 hyperintensities present on initial imaging in 23/34 patients (67%). Of the 23 patients with unexplained MRI findings, 15 (65%) had wedge-shaped T2 hyperintensities in the subcortical white matter extending to the cortex suggestive of a cortical dysplasia. 3 additional cases (17%) had a lesion within the cerebellum suggestive of a neuronal migration anomaly. In one patient where the MRI was suggestive of focal cortical dysplasia, histopathologic analysis revealed dysplastic glial foci without other alterations of cortical architecture or other cytologic abnormalities.

CONCLUSION

Unexplained T2 hyperintensities occur frequently in patients with NF-2. While they may not be the NF-2 equivalent of NF-associated bright spots seen in NF-1, some of these T2 hyperintensities in patients with NF-2 may represent underlying disorders of neuronal migration. Further studies are needed to validate our findings.

Sporadic meningioangiomatosis: imaging findings with histopathologic correlations in seven patients

INTRODUCTION

Meningioangiomatosis (MA) is a rare benign cerebral lesion. We aimed to evaluate the CT and MR features of sporadic MA, with a focus on the correlation between imaging and histopathologic findings.

METHODS

CT (n = 7) and MR (n = 8) images of eight patients (6 men and 2 women; mean age, 12.8 years; range, 4-22 years) with pathologically proven MA were retrospectively reviewed. After dividing the MA lesions according to their distribution into cortical and subcortical white matter components, the morphologic characteristics were analyzed and correlated with histopathologic findings in seven patients.

RESULTS

CT and MR images showed cortical (n = 4, 50%) and subcortical white matter (n = 7, 88%) components of MA. All four cortical components revealed hyperattenuation on CT scan and T1 isointensity/T2 hypointensity on MR images, whereas subcortical white matter components showed hypoattenuation on CT scan and T1 hypointensity/T2 hyperintensity on MR images. Two cortical components (25%) demonstrated enhancement and one subcortical white matter component demonstrated cystic change. Seven cases were available for imaging-histopathologic correlation. In all seven cases, the cortex was involved by MA and six patients (86%) showed subcortical white matter involvement by MA. There were excellent correlations between the imaging and histopathologic findings in subcortical white matter components, and the accuracy was 100% (seven of seven); whereas there were poor correlations in cortical components, and the accuracy was 43% (three of seven).

CONCLUSIONS

The cerebral cortex and subcortical white matter were concomitantly involved by MA. Subcortical white matter components of MA were more apparent than cortical components on CT and MR imaging.

Multifocal meningioangiomatosis in a 3-year-old patient

Meningioangiomatosis consists of benign hamartomatous lesions of the brain and the leptomeninges, which typically present with seizure. Management is predicated on resection and control of seizures with medication. Lesions are typically solitary. Multifocal meningioangiomatosis is extremely rare, with only 2 cases reported in adults and none in children. The authors report the first case, to their knowledge, of multifocal meningioangiomatosis in a child. This unique case highlights therapeutic challenges associated with these lesions and demonstrates that multifocality is possible in the pediatric population. This finding has implications for diagnosis and follow-up for children afflicted with these tumors.

Clinicopathological features of meningioangiomatosis associated with meningioma: a case report with literature review

Aim. To analyze the clinicopathological features of meningioangiomatosis (MA) associated with meningioma. Methods. We present one case of MA associated with meningioma. Histopathological examination and immunohistochemistry were used. Results. The age of the patient was 33-year-old man. Histopathologically, MA was characterized by vascular proliferation with perivascular meningothelial cells and/or fibroblast proliferation, entrapped glial islands. In addition, MA was associated with transitional meningioma. The patient was alive without evidence of recurrence at 18 months after mass resection. Conclusion. MA associated with meningioma is an extremely rare lesion. The differential diagnosis includes cortical invasion by meningioma and intracerebral schwannoma. Patients with MA associated with meningioma often have a good prognosis after operation.

Meningioangiomatosis: a case report and literature review emphasizing diverse appearance on different imaging modalities

Purpose. Meningioangiomatosis (MA) is a rare, benign lesion that commonly mimics other intracranial malformations in clinical presentation and appearance on imaging. The case presented and the literature review performed highlight the importance of combining MRI and CT results to better characterize intracranial lesions and including MA on the list of differential diagnoses of patients presenting with seizures. Methods. The case described is of a 19-year-old male with a 10-year history of worsening seizures refractory to multiple drug regimens. MRI revealed an atypical vascular malformation. The patient underwent surgical resection of the epileptogenic cortex. Results. Although the radiologic impression of the lesion was a vascular malformation, pathological examination revealed MA. A literature search performed highlights the variability of the appearance of MA on CT and MRI and suggests the utility of the T2 GRE sequence in illustrating the presence of calcification and, in a lesion with other characteristic features, the diagnosis of MA. Conclusion. MA can be a difficult diagnosis to make based on imaging findings alone. However, in a patient with a characteristic history and presentation, the presence of a calcified mass on CT and MRI brain susceptibility artifact on a T2 GRE sequence may suggest MA.