Aggressive natural killer cell leukemia/lymphoma: a comprehensive cytogenetic study by spectral karyotyping

A 38-year-old male presented with fever and hepatosplenomegaly. Cells that had infiltrated to the bone marrow were consistent immunophenotypically and genotypically with natural killer (NK) cells. Oligoclonal Epstein-Barr virus infection was detected in the bone marrow cells. The patient was diagnosed as a case of aggressive NK cell leukemia/lymphoma. Combined chemotherapy was not effective and death occurred shortly after presentation. Although the karyotype of this case was too complicated to be accurately identified only by G-banding, spectral karyotyping (SKY) analysis not only identified all chromosomal materials of unknown origin, but also detected the cryptic translocation on the apparently normal chromosome. Moreover, SKY analysis identified der(4)t(4;14)(q12;q11.2). The chromosomal band 14q11.2 is a recurring breakpoint in T-cell non-Hodgkin's lymphoma, and is also the locus of the delta chain of the T-cell receptor. To our knowledge, t(4;14)(q12;q11.2) in T-cell or NK-cell malignancies has not been previously reported.