Simultaneous occurrence of large B-cell non-Hodgkin lymphoma and myelodysplastic syndrome rapidly evolving into acute myeloblastic leukemia.

We describe a case of simultaneous occurrence of large B-cell non-Hodgkin lymphoma and myelodysplastic syndrome in the absence of previous chemotherapy or radiotherapy. After initiation of steroid treatment, the myeloid clone showed a rapid increase in both the bone marrow and peripheral blood with transformation into acute myeloid leukemia. The diagnosis were confirmed by immunophenotypic studies performed in the histologic sections of the lymph node, as well as in bone marrow and peripheral blast cells. This case may be indicative of potential down-regulation of a malignant myeloid clone induced by the malignant lymphoid clone.