Abstract
We report two cases of acute lymphoblastic leukemia (ALL) that were difficult to diagnose, because the patients presented only cytopenia without the appearance of distinct blast cells in peripheral blood and bone marrow for more than five months. The first case was a 23-month-old girl. She was noted to have bicytopenia and admitted to our hospital when she had a fever. She did not present an obvious increase of blast cells at the time of admission. However, after seven months, blast cells increased suddenly and she developed typical manifestations of ALL. The second case was a 26-month-old boy. He was kept under observation in another hospital because he presented bicytopenia like the first case. After five months, he had overt ALL. These two cases corresponded to the PreALL described previously. ALL preceded by a cytopenic phase seems to have a good prognosis. The cases which we experienced were common ALL, and responded well to chemotherapy, which resulted in complete remission. One case in which chromosome analysis was carried out showed hyperdiploidy, known as a good prognostic factor.
