Histologically classified XXXX of the brain: a controversy.

@entity1 @entity4798 @entity410 @entity2758 @entity66 @entity548 @entity8721 @entity4 @entity600 @entity6623 @entity2477 @entity1211 @entity1462
The term " @entity6623 " (VA) usually refers to a @entity600 ( @entity600 ). However, a group of @entity1462 called VAs shows no @entity66 on angiography. The clinical and histological features of histologically classified VAs were studied in eight @entity1 who presented with @entity548 or @entity410 to reevaluate these @entity1211 . Angiography showed no @entity66 in six @entity1 . Histological study included immunostaining for smooth muscle actin and glial fibrillary acidic protein. Surgical specimens of 10 cases of @entity2477 , 10 cases of @entity2758 , and two cases of @entity8721 were studied to compare these types of VAs. Angiographically occult VAs were surgically removed safely, whereas removal of DVAs was complicated by @entity4 and @entity4798 . Histological examination found angiographically occult VAs contained malformed and compactly arranged vessels with partly degenerated walls, whereas DVAs had dilated thin-walled vessels that were diffusely distributed in the normal white matter. This study of our cases and a review of the reported cases of VAs suggests that two different clinical and pathological entities are commonly categorized as "VA," angiographically occult VAs and DVAs. These two entities should be carefully distinguished.
