OBJECTIVE: To examine the etiology of and clinicopathologic findings associated 
with meningioangiomatosis and to evaluate MIB1 immunoreactivity (marker of cell 
proliferation) in this lesion.
DESIGN: Retrospective surgical pathology series of three patients.
SETTING: Tertiary referral center with a high volume of epilepsy surgery.
PATIENTS: Individuals with meningioangiomatosis who underwent surgical resection 
of the lesion.
RESULTS: Three patients aged 11, 14, and 32 years (two females, one male) 
comprise the study. All patients presented with a history of intractable 
seizures (2, 3, and 30 years duration). None of the patients had von 
Recklinghausen's disease. All three patients underwent gross total resection of 
the lesion, and postoperative seizure-free intervals range from 7 to 15 months. 
Histologically, the lesion is characterized by a proliferation of blood vessels 
and meningothelial cells arranged around vessels in the meninges, cortex, and 
underlying white matter. Psammoma body formation or dystrophic mineralization 
and gliosis of the intervening parenchyma was observed in all three cases. 
Bodian stains failed to demonstrate neurofibrillary tangles within intervening 
parenchymal neurons. Focal epithelial membrane antigen positivity was observed 
in two lesions and was absent in one. MIB1 staining was observed in two lesions 
(MIB1 index = 0.8 and 0.6) within the meningothelial cell nuclei and was absent 
in one case.
CONCLUSIONS: Meningioangiomatosis is a rare malformative or hamartomatous lesion 
of the central nervous system characterized by a proliferation of vessels and 
perivascular cuffs of meningothelial cells. Absent MIB1 immunoreactivity or low 
MIB1 indices in the lesion support the clinical impression of a slow-growing 
lesion and further support a malformative or hamartomatous etiology.