In this paper, the authors reported four cases of choroid plexus angioma which were detected by computerized tomography and were excised surgically. These four cases had the following characteristic CT findings. The initial CT scan showed intraventricular hemorrhage with or without intracerebral hematoma in each case. More than two weeks later, when the intraventricular hemorrhage had disappeared completely on the plain CT scan, a small high density area corresponding to the site of the angioma was demonstrated on the contrast enhancement CT scan. An angiomatous stain was also visualized on the angiogram in two of the four cases. In one case, vertebral angiography showed an arteriovenous malformation in the fourth ventricle supplied by the bilateral posterior inferior cerebellar artery, and in the other, right carotid angiography revealed a faint angiomatous stain in the plexal segment of the anterior choroidal artery. Each patient underwent a successful operation on the angioma located in the fourth ventricle, the left trigone, the right trigone and the right trigone of the lateral venticle respectively. The histological diagnosis of the excised specimens was arteriovenous malformation in all four cases.
Twelve reported cases with CT findings of choroid plexus angioma were reviewed, which were verified histologically. Among 16 cases including the four present ones, contrast enhancement CT (CE CT) scan was performed in 11 cases. In eight of the 11 cases (73%), a small highly density area corresponding to the site of the angioma was demonstrated on CE CT scan, while angiography revealed an angiomatous stain in only six of 14 cases (43%).
Our conclusion is as follows. In cases of intraventricular hemorrhage with or without intracerebral hematoma, choroid plexus angioma should be considered as one of the causes of bleeding, even though it is supposed to be uncommon. In such cases, CE CT scan should be performed to detect the lesion of the angioma, especially in the late stage, when the hemorrhage have disappeared completely on a plain CT scan. Surgical removal of the angioma is recommended because of the high incidence of recurrent and fatal hemorrhage.
