Meningioangiomatosis: Multimodal Analysis and Insights From a Systematic Review

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.

Pediatric meningiomas: A literature review and diagnostic update

Background

Meningiomas have always represented the most frequently observed primary central nervous system (CNS) tumor in adults. Multiple advances concerning the genetic and epigenetic characterizations of adult meningiomas have been made over the last few years, and a new proposition for integrated histo-molecular grading has recently been offered in the literature. Pediatric meningiomas represent a very small proportion of all diagnosed meningiomas. New literature has determined that pediatric meningiomas are clinically, histopathologically, genetically, and epigenetically distinct from their adult counterparts. Herein, we reviewed and performed a synthesis of literature investigating pediatric meningiomas. We then compared and contrasted pediatric meningiomas with their adult counterparts.

Methods

We performed an extensive review of cases from English-language literature available in Pubmed using the keywords "pediatric" and "meningioma" as well as "children" and "meningioma". We reviewed and analyzed fifty-six papers that include 498 cases.

Results

This literature review revealed that pediatric meningiomas differ from their adult counterparts clinically (location, sex ratio) and also in terms of etiology (germline mutations), histopathology (a greater incidence of clear cell subtype), molecular biology, and epigenetics.

Conclusions

Pediatric meningiomas are, like other brain tumors (such as low-grade and high-grade gliomas), clinically and biologically different from their adult counterparts. Further studies are needed to better understand the tumorigenesis of pediatric meningiomas and to optimize their stratification in terms of outcome and therapeutic strategy.

Pure and non-pure meningioangiomatosis of 36 Chinese patients: an analysis of clinical presentation, diagnosis, histopathology and prognosis

Meningioangiomatosis (MA) is a disease that is extremely rarely reported. Sporadic MA is occasionally combined with meningioma or other lesions (identified as non-pure MA). This retrospective study investigated the difference between pure MA and non-pure MA by exploring clinical manifestations, histopathology characteristics, and outcomes of MA after surgery. We reviewed the medical records of 36 histopathologically confirmed MA patients (18 pure MA and 18 non-pure MA) who received surgery at our institution between 2012 and 2021. We compared differences in demographic, clinical, imaging, pathological features, and surgical outcomes between pure MA and non-pure MA through descriptive statistics. Compared to non-pure MA, pure MA presented with a more prominent male predilection (5:1 vs. 1.57:1, P = 0.264), a higher seizure incidence (83.3% vs 50.0%, P = 0.038), a more seizure type of GTCS (14/15 vs 5/9, P = 0.047), a less prominent enhancement on MRI (27.8% vs 88.9%, P < 0.001) and a preference of temporal and frontal lobe (100% vs 44.4%, P < 0.001). The differences in clinical characteristics between pure MA and non-pure MA demonstrate their disparate biological natures. Pure MA seems to be a non-neoplastic lesion, while non-pure MA is commonly combined with meningioma, which is a neoplastic lesion. A correct differential diagnosis can be achieved via a triad of the type of seizure, the location of lesion and the radiological presentation. MA is curable and the prognosis is excellent as most patients are free of seizure and recurrence after surgical treatment.

Encephalic meningioangiomatosis in a cat

Meningioangiomatosis (MA) is a rare proliferative meningovascular entity that has been described mainly in humans and dogs. Here we describe MA in a 13-y-old spayed female domestic shorthaired cat that died 5 d after acute change in behavior, open-mouth breathing, seizures, hyperthermia, and inability to walk. On MRI, the lesion appeared predominantly as extraparenchymal hemorrhage. Autopsy changes consisted of a dark-red, hemorrhagic plaque that expanded the leptomeninges and outer neuroparenchyma of the right piriform and temporal telencephalic lobes, chalky white nodules in the peripancreatic fat, and yellow fluid in the abdomen. Histologically, the lesion in the brain consisted of leptomeningeal thickening by spindle cells that effaced the subarachnoid spaces and extended perivascularly into the underlying cerebral cortex. Spindle cells were arranged as streams or whorls around blood vessels, and had slender eosinophilic cytoplasm and elongated nuclei with coarsely stippled chromatin and 1 or 2 distinct nucleoli. There was extensive hemorrhage, clusters of hemosiderin-laden macrophages, and mineralization throughout. Spindle cells had positive immunolabeling for vimentin. A striking MRI and gross feature in our case was the extensive hemorrhage associated with the MA lesion. Additional findings included suppurative pancreatitis with peritonitis and supraspinatus myonecrosis.

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.