[1] Aiiku Hosp, Blood Disorders Ctr, Chuo Ku Minami 4 Nishi 25, Sapporo, Hokkaido 0640804, Japan
[2] Hokkaido Univ, Fac Med, Dept Canc Pathol, Sapporo, Hokkaido 0608638, Japan
[3] Hokkaido Univ Hosp, Dept Surg Pathol, Sapporo, Hokkaido 0608648, Japan