Acute myelofibrosis. A report of four cases and review of the literature.

Overview

Four new cases of acute myelofibrosis are reported, and 63 cases reported in the literature are reviewed. The typical features of this disease include a rapidly progressive clinical course; nonspecific symptoms such as weight loss, anorexia, fatigue and weakness; the absence of organomegaly; pancytopenia; circulating blast cells; and mild abnormalities in the red blood cell morphology. The bone marrow aspirates are usually "dry." The bone marrow biopsies are essential for the diagnosis and show four consistent features: hypercellularity, reticulin fibrosis, proliferation of blast cells and bizarre, atypical megakaryocytes. In 16 cases, the blast cells in peripheral blood and bone marrow, which are unclassifiable by conventional morphology, could be identified as megakaryoblasts by ultrastructural and immunocytochemical techniques. It is concluded that acute myelofibrosis is a definite clinicopathologic entity, which may be related to acute megakaryoblastic leukemia.