A case of acute myeloblastic leukemia with a novel variant of t(8;21)(q22;q22).
We encountered a case of acute myeloblastic leukemia (AML), with extramedullary leukemia (EML) and a masked type of the variant translocation t(8;21)(q22;q22). Morphologically, the AML M2 subtype according to the French-American-British (FAB) classification was present. Phenotypically, leukemic cells were negative for CD19 and positive for CD56. Clinically, the case showed chemo-refractoriness and a poor outcome. The initial karyotypic interpretation was t(8;9)(q22;q34) on G-banding. Multiplex-fluorescence in situ hybridization (multiplex-FISH) analysis revealed a three-way translocation involving chromosomes 8, 9, and 21, and identified a masked type of variant t(8;21)q22;q22) translocation. The karyotype was finally determined as 45,X,-Y,der(8)t(8;21)(q22;q22), der(9)(8;9)(q22;q34), and der(21)t(9;21)(q34;q22). Results of FISH using the AML1/ETO probe and detection of the AML1/ETO fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) support the karyotype as well as the sequence of the PCR product. Additionally, C-KIT mutation was detected.
Kawakami
Keiki
K
Division of Hematology and Oncology, Suzuka General Hospital, Suzuka, Mie, Japan. Kawakei@cocoa.ocn.ne.jp
Nishii
Kazuhiro
K
Hyou
Ryuu
R
Watanabe
Yasuyuki
Y
Nakao
Makoto
M
Mitani
Hidetsugu
H
Murata
Tetsuya
T
Monma
Fumihiko
F
Yamamori
Shunji
S
Hosokai
Noboru
N
Miura
Ikuo
I
D000328:Adult; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D006411:Hematopoiesis, Extramedullary / Q000235:genetics; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008297:Male; D011518:Proto-Oncogene Proteins / Q000235:genetics; D000075142:RUNX1 Translocation Partner 1 Protein; D014157:Transcription Factors / Q000235:genetics; D014178:Translocation, Genetic
D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; C493728:RUNX1 protein, human; C082222:RUNX1T1 protein, human; D014157:Transcription Factors