Surgical treatment of cryptic AVM's and associated hematoma in the brain stem and spinal cord.

Most surgically treated cases of brain-stem hematomas have been attributed to rupture of cryptic arteriovenous malformations (AVM's); however, very few cases have been histologically proven. Similarly, there are very few reports of surgically treated spontaneous hematomyelia, in which the hemorrhage has been histologically confirmed as being due to a purely intramedullary AVM. The authors report three cases with surgically treated, histologically confirmed AVM's, of which two were in the brain stem and the third was in the spinal cord. In all these cases, abnormal vascular tissue in the wall of the hematoma cavity was recognized at operation and excised.