Hemophagocytosis by leukemic megakaryoblasts in acute myeloid leukemia (megakaryoblastic) with t(1;22)(p13;q13);RBM15-MKL1

J Pediatr Hematol Oncol. 2012 Oct;34(7):576-80. doi: 10.1097/MPH.0b013e318245a027.

Abstract

Acute megakaryoblastic leukemia is a rare variant of acute myeloid leukemia, whereby leukemic blasts display characteristic morphologic and phenotypic features indicating megakaryocytoid differentiation. A distinct entity characterized by the t(1;22)(p13;q13) translocation, resulting in the RBM15-MKL1 fusion oncogene, has been recently recognized. This is predominantly a disease afflicting infants and displays characteristic clinical features. We present a case of acute megakaryoblastic leukemia with t(1;22)(p13;q13) along with a discussion of the current understanding of the molecular biology of RBM15-MKL1. This case also displayed striking and unusual morphologic appearances including extensive hemophagocytosis by leukemic blasts, which has not been previously reported for this particular type of leukemia.

Publication types

  • Case Reports

MeSH terms

  • Chromosomes, Human, Pair 1*
  • Chromosomes, Human, Pair 22*
  • Female
  • Humans
  • Infant
  • Leukemia, Megakaryoblastic, Acute / genetics*
  • Leukemia, Megakaryoblastic, Acute / pathology
  • Lymphohistiocytosis, Hemophagocytic / etiology*
  • Megakaryocyte Progenitor Cells / pathology*
  • Oncogene Proteins, Fusion / genetics
  • Translocation, Genetic*

Substances

  • OTT-MAL fusion protein, human
  • Oncogene Proteins, Fusion