5q- syndrome terminating in acute myeloid leukemia. Karyotype evolution and immunologic characterization of blast cells.

We report a case of 5q- syndrome that progressed to acute nonlymphocytic leukemia after 9 years of clinically and morphologically stable disease. The transition from the chronic to the leukemic phase was characterized by the appearance of an additional cytogenetic anomaly [inv(2)] in the cell carrying the 5q-, together with the expansion of a clone showing an apparently normal karyotype.