Abstract
A case of common acute lymphocytic leukemia, hardly differentiated from M5 in FAB classification is reported. A 3-year-old girl was referred to our hospital because of fever, anemia, and heart murmur at the end of December, 1985. Hepatosplenomegaly, lymphadenopathy, and pancytopenia (WBC 2, 600/mm3, RBC 1.96 × 106/mm3, P1 54 × 103/mm3) were observed. May-Giemsa-stained bone marrow smear demonstrated a predominance of large-sized leukemic cells (93.5%) with fine granules in relatively abundant cytoplasm and with coarse nuclear chromatin. Those granules showed positive a.-naphthyl butyrate esterase (ANBE) stain, and this reactivity was not inhibited by NaF. Surface marker studies revealed that 97% of blasts were positive for J5 (CALLA) and 48% for Ia (HLA-DR). The diagnosis was made as common acute lymphocytic leukemia (cALL), L2-type in FAB classification. She received chemotherapy according to the ALL standard risk group regimen of the 11 th protocol of Tokyo Children's Leukemia Study Group (TCLSG) and has achieved complete remission sustained for more than one year.
