Increased expression of vascular endothelial growth factor and its receptor in enlarging brain arteriovenous malformations--a case report.

CASE: A 24-year-old man with Spetzler-Martin (S-M) Grade III arteriovenous malformation (AVM). He was conservatively treated, but AVM significantly increased in size over 5 years, judged as Grade IV. Subsequently, he developed intracerebral hemorrhage. AVM was totally removed. Immunohistochemistry showed that the endothelial cells in the dura and nidus were positive for VEGF and VEGF-R.