[Megakaryocytic leukemia with thrombocytosis].
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 microliters) and a normal platelet count (21 X 10(4)/microliters). 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, alpha-naphthyl-butyrate 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 X 10(4) to 63 X 10(4)/microliters. 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.
Nakajima
M
M
Fukunaga
H
H
Amano
M
M
Fukuda
T
T
Ryo
R
R
D002454:Cell Differentiation; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000150:complications* / Q000473:pathology; D008297:Male; D008533:Megakaryocytes / Q000473:pathology; D008875:Middle Aged; D055728:Primary Myelofibrosis / Q000473:pathology; D013922:Thrombocytosis / Q000209:etiology*