1989 Volume 30 Issue 7 Pages 1084-1088
A 62-year-old man was admitted to our hospital with exertional dyspnea. On admission, neither hepatosplenomegaly nor lymphadenopathy were noted. Laboratory data revealed anemia (Hb, 4.8 g/dl), leukopenia (2,800/μl) and a normal platelet count (21×104/μl), The immature blast cells in the peripheral blood were 15%, which increased to 32% during his clinical course. On cytochemical studies, the blast cells had no staining with peroxidase, α-naphtyl-butylate esterase and PAS, although acid phosphatase was positive. More than 58% of the blasts were identified as being of megakaryocytic lineage by platelet peroxidase and by tests with monoclonal GP IIb/IIIa antibody. Bone marrow biopsy disclosed marked fibrosis. However, the patient constantly had normal counts of platelets ranging from 21×104 to 63×104/μl.
This case provides evidence that the megakaryocytic leukemias can be categorized into two types, which are characterized by either undifferentiated or differentiated megakaryocytic leukemia cells.
