Chronic encapsulated intracerebral hematoma associated with angiographically occult arteriovenous malformation--case report.

A 34-year-old female presented with a rare chronic encapsulated intracerebral hematoma associated with an angiographically occult arteriovenous malformation. A neovascularized fibrous capsule containing various stages of intracerebral hematoma formation was removed. These unusual entities mimic brain tumors or abscesses because of gradual growth and slowly progressive neurological deficits. Repeated bleeding or exudation from the capillaries of the capsule may allow expansion of the chronic encapsulated intracerebral hematoma.