[1] Tokyo Univ Hosp, Dept Neurosurg, Bunkyo Ku, Tokyo 1138655, Japan
[2] Tokyo Univ Hosp, Dept Pathol, Tokyo 1138655, Japan
[3] Massachusetts Gen Hosp, Dept Pathol, Boston, MA 02114 USA
[4] Univ Dusseldorf, Dept Neuropathol, Dusseldorf, Germany
[5] Int Med Ctr Japan, Dept Radiat Therapy & Oncol, Tokyo, Japan