Translocation t(8;16) in acute monocytic leukemia.

A report is given of three new cases of acute monocytic leukemia, FAB M5a, with a t(8;16)(p11;p13). Two cases showed a marked erythrophagocytosis, including one with phagocytosis of normoblasts and granulocytes. Phagocytosis was absent in the third case. The t(8;16) was the only abnormality in two cases, whereas one case showed clonal evolution with partial trisomy 1q and a deletion of part of the short arms of chromosomes 1 and 3. Treatment results and survival were poor in all cases. A complete remission was achieved in two patients, which lasted only for 3 and 6 months, respectively. In one of these cases a central nervous system relapse occurred. Survival was short, lasting between 1 and 9 months. One patient succumbed to interstitial pneumonitis, a complication of allogeneic bone marrow transplantation without evidence for relapsing leukemia.