FISH diagnosis of t(8;21) in a myelodysplasia secondary to Hodgkin lymphoma.

A t(8;21)(q22;q22) translocation without blood and bone marrow invasion by immature myeloid precursors was suspected in a conventional karyotype and confirmed by fluorescence in situ hybridization (FISH) with chromosome 8 and 21 painting in a patient previously treated for Hodgkin's lymphoma. Six weeks later, the diagnosis was confirmed by the onset of acute myeloid leukemia (AML) M2 with a t(8;21) in the bone marrow.