Paroxysmal nocturnal hemoglobinuria: termination in acute monocytic leukemia and reappearance after chemotherapy with N4-palmitoyl-1-beta-D-arabinofuranosylcytosine (PL-AC) and vincristine.

Acute monocytic leukemia developed in a 77-year-old woman about 18 months after a diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) had been made. The classical features of PNH disappeared with the onset of the leukemia. Chemotherapy with N4-palmitoyl-1-beta-D-arabinosylcytosine and vincristine resulted in the disappearance of leukemic cells in the bone marrow, during which time intravascular hemolysis recurred and the results of a Ham's test were again positive. The anemia and thrombocytopenia, however, were not improved. The present case report suggests the disappearance of the leukemic cells to imply not bone marrow remission but the return of PNH.