Surgery of angiomas in the brainstem with a stress on the presence of telangiectasia.

This report deals with the surgery of angiomas other than arteriovenous malformation in the brainstem. The surgical cases were three cavernomas, two telangiectasias, and two venous malformations. We performed surgery when an angioma bled and the resulting hematoma was situated near the surface of the brainstem or the fourth ventricle. The cases were operated on at the subacute or chronic stages after hemorrhage. Although a magnetic resonance (MR) image showed a subacute or chronic localized hematoma with a low intensity rim, the case was not always a cavernoma, but a telangiectasia. Cavernomas could be totally removed, but telangiectasia could not. In the cases of medullary venous malformation the diagnosis was obtained radiologically, and when the hematoma was large, only hematoma evacuation was performed. In all cases the postoperative Karnofsky scores were improved or unchanged. Postoperative rebleeding in the hematoma cavity continued insidiously in a case of telangiectasia. The abnormal vessels of telangiectasia in the brainstem were preoperatively not visualized by cerebral angiography or MR imaging, but became visualized by enhanced MR imaging after evacuation of hematoma in two cases. It is stressed that an angioma with a hematoma intensity core surrounded by a low intensity rim on MR images is not always a cavernoma, but possibly is a telangiectasia.