title: Extramedullary blast crisis derived from 2 different clones in the central nervous system and neck during complete cytogenetic remission of chronic myelogenous leukemia treated with imatinib mesylate.
abstract: We describe a patient with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) who developed an extramedullary blast crisis in the central nervous system (CNS) and then a subcutaneous tumor of the neck during treatment with imatinib mesylate. Administered 400 mg of imatinib mesylate after the diagnosis of chronic-phase CML, the patient achieved a complete cytogenetic remission 4 months later. However, he developed a mixed myeloid/B-cell blast crisis with additional karyotype abnormalities only in the CNS during a complete cytogenetic remission in the bone marrow. Several doses of intrathecal chemotherapy and whole-brain irradiation were effective in treating the blast crisis in the CNS. After 7 months of complete cytogenetic remission, the patient experienced a subcutaneous tumor in the right neck. A biopsy of the tumor revealed a mixed myeloid/T-cell blast crisis. The cytogenetic analysis showed that the blast crisis clone in the neck tumor was different from that of the CNS. An increased dose of imatinib mesylate was ineffective in treating the neck tumor. Irradiation to the right neck was therefore undertaken. This case suggests that the development of a clone resistant to imatinib mesylate is not always detected in the bone marrow and that multiple Ph-positive clones have the potential to become transformed into a blast crisis.
authors.affiliation: Division of Hematology, Nephrology and Rheumatology, Department of Internal Medicine, Kinki University School of Medicine, Osaka 589-8511, Japan. matsuda@int3.med.kindai.ac.jp
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Matsuda
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Morita
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shimada
authors.forename: Junichi
authors.initials: J
authors.lastname: Miyatake
authors.forename: Chikara
authors.initials: C
authors.lastname: Hirase
authors.forename: Miyako
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Tatsumi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Maeda
authors.forename: Akihisa
authors.initials: A
authors.lastname: Kanamaru
mesh_terms: D000293:Adolescent; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D001752:Blast Crisis / Q000235:genetics*; D016543:Central Nervous System Neoplasms / Q000235:genetics* / Q000473:pathology*; D002999:Clone Cells; D006258:Head and Neck Neoplasms / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D007621:Karyotyping; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D008297:Male; D010879:Piperazines / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate