Chronic encapsulated intracerebral haematomas.

We present four patients with uncommon encapsulated intracerebral haematomas (ICH). Because of ring enhancement, three were incorrectly diagnosed as gliomas and operated upon. In one case the diagnosis of chronic ICH was made on MRI. MRI can be used to demonstrate that a lesion is only a haematoma and is valuable in follow-up and in differentiating these haematomas from neoplasms. Angiography may reveal a vascular malformation which may be the reason for repeated bleeding, which may lead to encapsulation. The mechanism, however, remains unclear in most cases.