Philadelphia chromosome positive acute lymphoblastic leukemia showing normal karyotype in G-banding chromosomal examination before chemotherapy.
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.
Hato
Akio
A
Hematology/Oncology Division, Department of Medicine, Hyogo Medical Center for Adults, Akashi, Hyogo, Japan.
Murayama
Tohru
T
Nishikawa
Shinichiro
S
Kajimoto
Kazuyoshi
K
Gomyo
Hiroshi
H
Sugimoto
Takeshi
T
Mizuno
Ishikazu
I
Koizumi
Tamio
T
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