[An unusual child case of myeloid/natural killer cell precursor acute leukemia treated successfully with acute myeloid leukemia-oriented chemotherapy].

This study was aimed to identify the characteristics of childhood myeloid/natural killer cell precursor acute leukemia (M/NKPAL), and to summarize the therapeutical experiences of this rare hematologic malignancy. A child case of M/NKPAL accompanied by CNS leukemia was enrolled in this study, the therapeutic regiments and the results of long time following up were analysed and evaluated. The results showed that the unusual child case of M/NKPAL with CNS infiltration was diagnosed, showing immunophenotype of CD7(+), CD33(+), CD34(+), CD56(+), HLA-DR(+), MPO(-) and negative for other NK cell, T and B cell differentiation antigens; the chromosomal abnormalities were trisomy 8 and deletion of chromosome 12p. The child case was treated with daunorubicin and cytarabine, and achieved complete remission. Then, 5 courses of acute myeloid leukemia-oriented chemotherapy were given as consolidation chemotherapy, all of the 5 courses contained high dose cytarabine. This child case was given 9 times of lumbar puncture and intrathecal injection, besides these, this case was also given cranial radiotherapy with a dose of 36 Gy. After treated with these methods, the child case achieved long-term complete remission. It is concluded that the M/NKPAL is a rare disease with distinctive immunophenotypic characteristics, acute myeloid leukemia-oriented chemotherapy regimen with high dose of cytarabine may be able to induce long-term remission.