1. Department of Neurosurgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
2. Department of Neurosurgery, Nagasaki University Hospital, Nagasaki, Japan
3. Department of Radiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
4. Department of Pathology, Nagasaki University Hospital, Nagasaki, Japan
5. Department of Human Pathology, Graduate School of Medicine, Gunma University, Gumma, Japan; and
6. Department of Pathology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan