Abstract
Transient pancytopenia associated with bone marrow aplasia rarely develops to acute lymphoblastic leukemia (ALL) 3 to 6 months later. We present a 3-year-old girl who developed ALL 10 months after the onset of aplastic anemia. The patient showed pancytopenia without hepatosplenomegaly in May 2005. The bone marrow was very hypoplastic and did not contain leukemic or dysplastic cells. We diagnosed her as having an aplastic anemia. An immunosuppressive therapy achieved a good response and was transfusion-free. In February 2006, she complained of recurrent leg pain, and in March, she had anemia and thrombocytopenia. Leukemic cells were found in 94% of bone marrow cells. She was diagnosed with B-precursor ALL. A hyperdiploid karyotype abnormality found in overt ALL was the same as that in aplastic anemia. We propose that we should carefully observe a development to ALL in aplastic anemia with an abnormal karyotype for long periods when immunosuppressive therapy was effective.
