Trisomy 8 preceding diagnosis of acute nonlymphocytic leukemia by 2 years in a patient with multiple myeloma without cytological evidence of myelodysplasia.

A case of acute nonlymphocytic leukemia (ANLL) occurring 2 years after the diagnosis of multiple myeloma (MM) that had been treated by only one course of melphalan/prednisone chemotherapy is reported. Cytogenetic and fluorescence in situ hybridization analysis of peripheral blood cells revealed trisomy 8 as the sole cytogenetic defect at the time of diagnosis of ANLL. Two years earlier, when MM was diagnosed without any cytological evidence of co-existent myelodysplasia, chromosomal analysis of bone marrow cells showed the same pathological karyotype 47, XY, +8 in 14 of 20 mitoses studied. Our interpretation of this unusual cytogenetic finding is that at the time of diagnosis of MM, in spite of lacking cytological signs of myelodysplasia, an unrecognizable myelodysplastic syndrome must have been present which then evolved to ANLL.