title: Philadelphia chromosome positive acute lymphoblastic leukemia showing normal karyotype in G-banding chromosomal examination before chemotherapy.
abstract: A 29-year-old male was admitted because of thrombocytopenia. A diagnosis of acute lymphoblastic leukaemia was made on the basis of a 61.6% infiltration of leukemic cells in his bone marrow. Standard G-binding chromosome analysis of bone marrow cells revealed a normal karyotype. He received combination chemotherapy, and achieved hematological complete remission. However, chromosomal analysis of bone marrow cells after 2 courses of consolidation therapy showed the Philadelphia (Ph) chromosome in two cells out of 20 analysed. We retrospectively examined the sample of bone marrow cells before chemotherapy; It showed minor BCR/ABL positivity with FISH and RT-PCR methods. The Ph chromosome disappeared after consolidation chemotherapy and allogeneic bone marrow transplantation, but the Ph chromosome reappeared at relapse. We postulated that there were two clones, both a Ph-positive clone and Ph-negative clone. At the initial diagnosis, Ph chromosome was not detected because the G-banding method analyzed only metaphase cells, which contained few Ph-positive clones. In order to offer effective therapy with molecular targeting agents, in this poor prognostic disease, it is necessary to detect Ph chromosome before the first chemotherapy and BCR/ABL detection with FISH or RT-PCR methods appears more useful than G-banding chromosome analysis.
authors.affiliation: Hematology/Oncology Division, Department of Medicine, Hyogo Medical Center for Adults, Akashi, Hyogo, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Hato
authors.forename: Tohru
authors.initials: T
authors.lastname: Murayama
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nishikawa
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kajimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Gomyo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sugimoto
authors.forename: Ishikazu
authors.initials: I
authors.lastname: Mizuno
authors.forename: Tamio
authors.initials: T
authors.lastname: Koizumi
mesh_terms: D000328:Adult; D001853:Bone Marrow / Q000473:pathology*; D002871:Chromosome Banding; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007621:Karyotyping; D017254:Leukemic Infiltration / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D008297:Male; D010677:Philadelphia Chromosome; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods