Abstract
A 79 year-old-male admitted in May 1981 because of slight splenomegaly, leukoerythroblastic anemia with tear drop poikilocytosis and highly elevated serum LDH. Hematological examinations showed RBC 322×104/μl, platelets 1.4×104/μl and WBC 4,400/μl with 4.0% blasts. Bone marrow aspirations resulted in a dry tap. A biopsied specimen was compatible with early stage of myelofibrosis. A diagnosis of primary myelofibrosis was made from these observations and the result of ferrokinetic study. Hepatosplenomegaly and pancytopenia progressed gradually and blasts increased in number (<20%) during 2 years after diagnosis. Cytochemical characteristics of blasts were as follows: PAS (-), myeloperoxidase <3%, α-naphthyl butyrate esterase (-), α-naphthyl acetate esterase (±), naphthol AS-D chloroacetate esterase (-) and acid phosphatase (+)∼(±). These blasts were identified as megakaryoblasts by platelet peroxidase reaction which was positive in the nuclear membrane and endoplasmic reticulum. A distinct myeofibrosis was proved by second marrow biopsy in Dec. 1983. From his long clinical course and these laboratory findings, he seemed to have been suffering from megakaryoblastic leukemia which has induced myelofibrosis.
