Monomyelocytic leukemia in an untreated case of Waldenström macroglobulinemia.

The development of acute leukemia occurring in the presence of Waldenström macroglobulinemia has been reported only twice, occurring once after many years of treatment, and on the second occasion, simultaneously. The intention of this report is to record a case of spontaneous onset of acute monomyelocytic leukemia occurring in an untreated patient with Waldenström macroglobulinemia after four years of observation without intervening chemotherapy or radioactive therapy, and without the influence of any known carcinogens.