Multicystic meningioangiomatosis

Imaging of congenital and developmental cystic lesions of the brain: a narrative review

INTRODUCTION

Congenital and developmental intracranial cysts represent a large heterogenous group with varied presentations and etiologies. They can range from normal variants to pathologic lesions often associated with known congenital syndromes or acquired insults. While some are incidentally found, others are symptomatic or may become symptomatic over time. The preferred type of neuroimaging for timely diagnosis helps determine appropriate management and treatment, if indicated.

AREAS COVERED

In this narrative review article, authors present a comprehensive description of developmental cystic lesions. Imaging descriptions are provided for each type of cystic lesion as well as several representative images.

EXPERT OPINION

As advanced neuroimaging techniques become more ubiquitous in clinical use, more light may be shed on the natural history of certain intracranial cystic lesions throughout the lifespan. This includes prenatal imaging for early identification and prognostication to surveillance imaging into advanced age to ascertain associations of certain cystic lesions with age-related cognitive dysfunction.

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.

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).