Departments of Neurosurgery, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan

Hirokazu Takami, Akitake Mukasa, Shunsaku Takayanagi, Tsukasa Koike, Reiko Matsuura, Shota Tanaka & Nobuhito Saito

Department of Neurosurgery, Kumamoto University Hospital, Kumamoto, Japan

Akitake Mukasa

Department of Pathology, The University of Tokyo Hospital, Tokyo, Japan

Masako Ikemura & Tetsuo Ushiku

Department of Neurosurgery, Showa General Hospital, Tokyo, Japan

Gakushi Yoshikawa

Department of Pathology, Kyorin University Hospital, Tokyo, Japan

Junji Shibahara