Translocation (9;11)(p21;q23) in a child with acute monoblastic leukemia following 2 1/2 years after successful chemotherapy for neuroblastoma.

This is a case report of a 4 1/2-year-old boy who developed acute monoblastic leukemia 2 1/2 years after he had been treated successfully with combined chemotherapy for neuroblastoma. All analyzable bone marrow-derived metaphases had the karyotype 47,XY, + 8,t(9;11)(p21;q23). The rare occurrence of specific chromosomal translocations in leukemias following prior chemotherapy and/or radiotherapy and their possible clinical implications in such cases are discussed.