It has been still controversial that idiopathic acquired aplastic anemia is a definite clinical entity.
Analysis of 51 cases with idiopathic aplastic anemia for the period of 12 years between 1962 and 1972 in the Keio University Hospital led us to conclude that aplastic anemia consists of two types: one is genuine (typical) aplastic anemia, the other aplastic anemia syndrome (atypical aplastic anemia). The diagnosis of genuine aplastic anemia should be made at the presence of pancytopenia with relative lymphocytosis, a-(hypo-)plastic bone marrow picture and elevated serum iron, One should make a diagnosis of aplastic anemia syndrome when found any two of following itemes: 1) reticulocytosis. 2) absence of relative lymphocytosis 3) monocytosis 4) erythroblasts in peripheral blood. 5) erythroid hyperplasia of bone marrow prior to treatment 6) left shift of myeloid series in bone marrow. 7) normal level of serum iron 8) splenomegaly.
Aplastic anemia syndrome can terminate in acute myelogenous leukemia, paroxysmal nocturnal hemoglobinemia (PNH) or aplastic anemia PNH syndrome. A part of the syndrome may be curable.
Thus genuine aplastic anemia is a definite clinical entity and should be strictly separated from aplastic anemia syndrome.
