Insights into Meningioangiomatosis with and without Meningioma: A Clinicopathologic and Genetic Series of 24 Cases with Review of the Literature

Abstract

Meningioangiomatosis (MA) is a rare seizure-associated lesion of presumed hamartomatous or developmental origin. It is occasionally combined with a neoplasm, most commonly meningioma (MA-M). In the current study, we examined 24 cases (14 pure MA, 10 MA-M) using immunohistochemistry for merlin, protein 4.1 B, progesterone receptor (PR), and MIB-1, as well as FISH for NF2 and 4.1B gene dosages. Nine cases of MA-M (90%) had gene deletions (NF2/4.7B), protein losses (merlin/protein 4.1B), and/or PR positivity, with a similar or identical phenotype in both components. No PR positivity or gene deletions were seen in pure MAs, though merlin and/or protein 4.1B were immunonegative in six cases. Our data suggest that in most MA-Ms, the MA component is neoplastic, likely representing an exuberant perivascular pattern of spread from the meningioma, rather than an underlying hamartoma. This pattern of spread may be facilitated by meningiomas that are predominantly leptomeningeal or intracerebral in origin. It remains important to distinguish this pattern from true brain invasion, given the more ominous prognostic significance of the latter. In contrast, most perivascular spindled cells of pure MA are genetically and immunohistochemically similar to non-neoplastic meningothelial cells, consistent with current histogenetic theories.

Sporadic meningioangiomatosis with and without meningioma: analysis of clinical differences and risk factors for poor seizure outcomes

“…Occasionally, sporadic MA combines with a neoplasm, most commonly meningioma (MA-M) [2]. MA is usually considered a benign, nonneoplastic lesion, while genetic and molecular studies have suggested that MA-M may be a neoplasm [3][4][5]. Given the neoplastic nature of MA-M, it is reasonable to assume that the clinical features of MA-M may be different from those of pure MA.…”

Tumors of the Central Nervous System

“…These tumors should not be viewed as meningioma with brain invasion corresponding to WHO grade II [ 227 ]. Although a correlation of prognosis with WHO histologic grade exists, the correlation is not is strong as in adult cases.…”

“…Although these tumors are intraparenchymal, they should not be viewed as brain invasion [ 227 ]. These tumors radiographically and pathologically mimic invasive meningiomas [ 227 ]. The meningioangiomatosis component in cases associated with meningioma appears to be neoplastic in nature in comparison to cases of pure meningioangiomatosis [ 227 ].…”

“…In rare occasions, meningioma may arise from meningiomatosis. Although these tumors are intraparenchymal, they should not be viewed as brain invasion [ 227 ]. These tumors radiographically and pathologically mimic invasive meningiomas [ 227 ].…”

Classification and pathological characteristics of the cortical dysplasias

“…Meningioangiomatosis is a rare disorder marked by a proliferation of blood vessels surrounded by collars of meningothelial cells. There is an association of the entity with neurofibromatosis type II and with overlying meningiomas [32]. Again, the phenotypic appearance of the FCD adjacent to these lesions most commonly resembles the type I FCD patterns; although the type IIa pattern has been described in some cases of meningioangiomatosis [5].…”