Focal cortical dysplasia in meningioangiomatosis

Meningioangiomatosis is a rare, benign, developmental, or hamartomatous lesion which may involve the leptomeninges and underlying brain parenchyma. Histologically, meningioangiomatosis is marked by a proliferation of blood vessels in the parenchyma, rimmed by collars of spindled meningothelial cells. There are anecdotal reports of an association of meningioangiomatosis with focal cortical dysplasia. We retrospectively analyzed the clinical, histopathologic, and treatment outcomes of 16 patients with a diagnosis of meningioangiomatosis, specifically investigating these cases for evidence of adjacent focal cortical dysplasia. Patients ranged in age from 1 to 34 years (median 18), 12 of whom had medically-intractable epilepsy as their presenting symptom. No patients in this study had a confirmed diagnosis of neurofibromatosis type II. Four patients (25%) were found to have fibrous meningiomas associated with the meningioangiomatosis. Ten of the 12 patients (83%) who had adequate tissue excised adjacent to the meningioangiomatosis demonstrated evidence of focal cortical dysplasia, with 6 of those (60%) classified as Palmini type IA, and 4 patients (40%) classified as Palmini type IIA. Seven of the patients (44%) had no post-operative seizures, and were off anti-epileptic drugs, while 2 patients relapsed, and required pharmacologic treatment for seizure control. This study therefore presents evidence to support inclusion of meningioangiomatosis as a focal cortical dysplasia-associated entity, as suggested by the ILAE classification (type IIIc). As focal cortical dysplasia is a developmental malformation, its association with meningioangiomatosis supports a developmental etiology of sporadic meningioangiomatosis.