Derivative (11)t(7;11)(q11;q24) in a child with acute megakaryoblastic leukemia

We document the clinical, morphologic, and cytogenetic findings in a 2 1/2-year-old patient with acute megakaryoblastic leukemia. Cytogenetic analysis of peripheral blood leukemic cells revealed the presence of a der(11)t(7;11)(q11;q24). Chromosome 7 involvement is observed in nearly half of all cases of megakaryoblastic leukemias, however, the type of abnormality differs widely from one case to another. The der(11)t(7;11)(q11;q24) described here is the first reported to our knowledge.