...Hiroyuki Takahira; Keisuke Shibata; Jouji Hirata; Tsukuru Umemura; Junji Nishimura; Hajime Nawata A 24-year-old man with Philadelphia-chromosome (Ph)-negative chronic myelocytic leukemia (CML) developed lymphoid blast crisis. In the chronic phase, karyotype was normal and the clinical...

... on 22qll, forming the BCR/ABL fusion gene. The Ph chromosome once detected rarely disappears, except as a result of therapy. We present an unusual Ph-positive CML case, which developed lymphoid blast crisis in complete cytogenetic remission following interferon-α and hydroxyurea therapy. Sequential...