[Myelofibrosis associated with immunological abnormalities]

A 74-year-old man was admitted to the National Defense Medical College Hospital because of purpura on the extremities. The blood hemoglobin level was 11.5 g/dl, the white blood cell count 7. 3 x 10(9)/l with 3% blastic cells, and the platelet count 4.0 x 10(9)/l. There was leukoerythroblastosis with only mild teardrop appearance of erythrocytes. The blastic cells consisted of two types, megakaryoblast-like cells and myeloblast-like cells. There was a very mild hepatosplenomegaly, but no lymphadenopathies. The bone marrow aspirations yielded dry taps. The marrow biopsy specimen revealed myelofibrosis associated with trilineage hyperplasia, but no apparent infiltration of leukemic cells. Platelet-associated IgG (PAIgG) had a high titer and the response to platelet transfusions was poor. On prednisolone and colchicine, the blastic cells in the peripheral blood disappeared and the platelet count increased. He died of pneumonia. The autopsy showed myelofibrosis with hyperplasia of myeloid and erythroid lineage in the bone marrow. Megakaryocytes were relatively few and there was no infiltration of leukemic cells.