Childhood myeloid/natural killer precursor acute leukemia with novel chromosomal aberrations der(5)t(4;5)(q31;q31.3) and t(14;17)(q32;q23)

We report a unique case of childhood acute leukemia. The leukemia blasts had lymphoblastoid appearance and expressed CD33, CD13, CD34, CD4, CD7, and CD56. The morphology and immunophenotype were most consistent with myeloid/natural killer precursor acute leukemia. The blasts had a complex karyotype, including two chromosomal aberrations, der(5)t(4;5)(q31;q31.3) and t(14;17)(q32;q23), not previously described in childhood acute leukemia. The patient achieved morphological remission following myeloid-based leukemia therapy.