A Case of Masked t(8;21) in Acute Myeloid Leukemia with Cytogenetic Abnormality of 45,X,-Y,t(8;17)(q22;p13)

ABSTRACT

The t(8;21)(q22;q22) is one of the most frequent structural chromosomal anomaly found in AML, occurring in about 5% of all AML and in 10% of AML with maturation (M2). And approximately 3.4% of AML with t(8;21)(q22;q22) occurs as a complex chromosomal abnormality and occasionally shows discrepancy between cytogenetic and molecular genetic analyses. We report a case of 42 yr old male patient that revealed morphological characteristics of AML-M2 and karyotypic abnormality of 45,X,-Y,t(8;17)(q22;p13) without visible involvement of chromosome 21 by conventional cytogenetic study with masked t(8;21) identified by FISH using RUNX1/RUNX1T1 probes. FISH confirmed nuc ish (RUNX1T1x3),(RUNX1x3), (RUNX1T1 con RUNX1x1). According to the results of conventional cytogenetic and FISH analyses, the karyotype was revised to 45,X,-Y,t(8;17;21)(q22;p13;q22).