Myelofibrosis in Chronic Granulocytic Leukemia

In 181 patients with chronic granulocytic leukemia (CGL) 39 patients demonstrated myelofibrosis (MF) during the course of their disease. These groups can be divided into two groups: one group initially presenting with the clinical and laboratory findings of CGL but with concomitant MF and a second group in whom MF developed late in the course of CGL. The occurrence of MF with CGL was associated with three findings: (1) elevation of the leukocyte alkaline phosphatase, (2) a very poor prognosis and (3) the frequent association of MF and blastic transformation of CGL. MF should be considered an integral part of CGL and when present should be considered part of the terminal phase of CGL and treated accordingly.