Purpose : We studied MR images of metastatic skull tumors to elucidate their features. Subjects and Methods : Eighty patients with metastatic skull tumors were found on routine head MR images since September 2002 to March 2004. Contrast-enhanced study with fat suppression was used in cases when required. The MR findings of the tumors were classified into four categories : local intraosseous, local invasive, diffuse intraosseous, and diffuse invasive types. Tumor localization was determined either in calvarium or skull base. Results : Primary sites were breast cancer (60%), lung cancer (15%), malignant lymphoma (6%), prostate cancer (5%), and others. Calvarial local intraosseous type was found most frequently (32%). The patients were mainly asymptomatic. However, a few had headache and nausea due to diffuse invasive type tumors, and others suffered from cranial nerve palsies that deteriorate their quality of life due to skull base tumors. Conclusion : Metastatic skull tumors are not rare. MR images contribute to understanding their localization, multiplicity, and also their relation to the brain, cranial nerves, and dural sinuses.

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This article focuses on the surgical techniques to treat the large basilar bifurcation aneurysms. Because of their complexity, their treatment requires careful surgical planning and the use of various surgical adjuncts. We prefer to use the subtemporal approach for large basilar bifurcation aneurysms, because it provides a wide operative field and facilitates ample exposure, dissection, and final clipping of the aneurysm. It is considered that routine use of intraoperative angiography and endoscope is very important for preservation of the parent artery, its branches, and perforators from the P1 segment of the posterior cerebral artery.

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The case of a 27-year-old man with sinus thrombosis caused by protein C deficiency is reported. He suffered seizure, headache and higher brain functional disorder. T2 weighted MR image showed disappearance of flow void in right sigmoid sinus and magnetic resonance venography (MRV) revealed dural sinus thrombosis from the superior sagittal sinus to the right sigmoid sinus. Cerebral angiography confirmed these findings and delay of cerebral circulation time with collateral venous drainage. Xenon-enhanced computed tomographic measurement of cerebral blood flow demonstrated whole brain ischemia. Coagulation studies revealed decreases in both protein C antigen level and activity. The same results were obtained from a study of the patient's mother. Prior to obtaining coagulation study results, he was treated with glycerol and continuous intravenous heparin injection. Headache diminished but did not disappear. After administration of continuous intravenous urokinase, headache disappeared. Magnetic resonance venography demonstrated sinus re-canalization. Management of patients with protein C deficiency is often problematic due to the risk of warfarin-induced skin necrosis. To avoid this complication, oral administration of warfarin was started at low dosage, progressively increasing daily doses with co-administration of heparin. Treatment of this rare disease thus proved successful, and he has been followed up with no subsequent problems.

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A 55-year-old woman visited our hospital with exophthalmos and hyperemia of her right eye. An angiogram demonstrated a high-flow right carotid-cavernous fistula (CCF) which was draining into the right superior ophthalmic and facial vein. We performed trans-arterial embolization using various kinds of coils, and completely obliterated the CCF. The CCF seemed to result from a rupture of a petrous portion aneurysm of the right internal carotid artery. Right internal carotid angiogram eight months after the embolization showed neither recanalization of the CCF nor coil compaction. Her symptoms disappeared within 12 months after the embolization. CCF caused by the rupture of an internal carotid artery aneurysm is a rare condition. High-flow CCFs with a large amount of arterio-venous shunt rarely resolve spontaneously. An endovascular approach is a useful treatment option for these CCFs.

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Traumatic intracranial aneurysms have been reported to have a poor prognosis due to delayed rupture. We report here two cases of ruptured traumatic anterior cerebral artery (ACA) aneurysms that were successfully treated by direct neck clipping. A 16-year-old girl and a 22-year-old man presented with subarachnoid hemorrhage 26 days and 76 days after blunt head injuries, respectively. In the former case, angiography demonstrated two distal ACA aneurysms; one was a right A2 aneurysm with a diameter of 10mm and the other was a left A2 aneurysm with a diameter of 2mm. On the 46th day after the head injury, the aneurysms were explored via an interhemispheric approach, following an A3-A3 side-to-side anastomosis performed in advance for prevention of ischemia during a relatively long temporary or permanent occlusion of the A2. The right A2 aneurysm was thrombosed and larger than shown on angiograms; neck clipping was successfully performed by intraaneurysmal thrombectomy under aneurysm trapping. The right A2 aneurysm was clipped without any difficulties. In the latter case, an A3 aneurysm with a diameter of 5mm was revealed by angiography. On the 97th day after the head injury, the aneurysm was explored via an interhemispheric approach. Like the former case, the aneurysm was thrombosed and larger than shown on angiograms. Neck clipping was performed while maintaining patency of the A3, following intraaneurysmal thrombectomy under aneurysm trapping. The pathological diagnoses were pseudoaneurysms consisting of thick connective tissues in both cases. The clinical course had no troubles with good activity of daily life. In conclusion, traumatic cerebral aneurysms may be thrombosed pseudoaneurysms. These aneurysms can be clipped following intraaneurysmal thrombectomy. However, cerebrovascular reconstruction should be considered to prevent ischemia in the area distal to the lesions.

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A patient who developed symptomatic intratumoral hemorrhage six years after gamma knife surgery for acoustic neurinoma is presented. The patient was a 72-year-old woman who was diagnosed with right acoustic neurinoma and underwent gamma knife surgery. Since symptomatic intratumoral hemorrhage was confirmed six years later, tumor resection was performed. Pathological analysis confirmed widespread hyaline thickening of the vascular endothelia. Symptomatic intratumoral hemorrhage is a relatively rare complication of schwannoma. The pathological features of spontaneous hemorrhage include such vascular anomalies as angioma, clusters of telangiectasia-like abnormal vessels, or numerous thin-walled, dilated vessels. In the present patient, hyaline thickening of vascular endothelia was noted. The association between this histological feature and spontaneous bleeding in neurinoma has not been previously reported in the literature. Delayed effects of radiation include hyaline thickening of the vascular endothelia and narrowing of the vascular lumen. These histological changes have been reported to occur in intratumoral hemorrhage in malignant brain tumors. In the present patient, as hyaline thickening of vascular endothelia due to the gamma knife surgery might have been implicated in symptomatic hemorrhage, the relationship between irradiation and symptomatic intratumoral hemorrhage was examined with reference to the relevant literature.

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We report a case of stoma obstruction 3 years after endoscopic third ventriculostomy. A 13-year-old male had received endoscopic third ventriculostomy for obstructive hydrocephalus due to pineal germinoma. Germinoma was thought diagnosed by endoscopic finding and treated by chemotherapy and stereotactic radiosurgery. After that, the tumor disappeared completely and there was no recurrence. Three years after treatment, the patient experienced headache and visual disturbance. Neurologic examination showed papilledema and MRI showed ventricular dilatation, disappearance of the flow void at the third ventricle, and dullness of infundibular recess angle, which indicated closure of the stoma. The patient received endoscopic third re-ventriculostomy and his symptoms improved. We discussed strategies for failure of endoscopic third ventriculostomy.

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A 23-year-old woman with cranial fasciitis is described. Although cranial fasciitis commonly occurs in childhood, this patient was referred to our hospital for a rapidly growing mass which arose in the temporal scalp within a 2 month period. She had no neurological deficits and magnetic resonance imaging demonstrated a ring-enhanced mass attached to the right temporal muscle. Surgical resection was performed and pathological examination revealed cranial fasciitis.

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