Cystic fibrosis complicated by acute leukemia.

During a 3-month period, two men ages 20 and 25 years, respectively, with cystic fibrosis developed acute lymphocytic and nonlymphocytic leukemias, respectively. These two patients were among 120 patients who attended our cystic fibrosis clinic during the last 3 years. Thirty-five of the 120 patients have survived beyond the second decade. The authors ask whether acute leukemia will be recognized with increasing frequency in cystic fibrosis patients who achieve prolonged survival.