A 12-year-old girl was admitted to our clinic because of fever and anemia in October, 1976. On hematological studies, including morphological, cytochemical and electron microscopical examinations, she was diagnosed as acute lymphoblastic leukemia (ALL) although thrombocytosis and a high level of serum vitamin B12, atypical features of ALL, were demonstrated.
Complete remission was achieved rapidly with vincristine and prednisolone treatment. After approximately 6 months of complete remission, the peripheral blood gradually showed chronic granulocytic leukemia (CGL) features and the Philadelphia chromosome was demonstrated on bone marrow cytogenetic studies. She was treated with busulphan and was in good health until October, 1977, when she developed “lymphoblastic” meningeal leukemia without any prior evidence of blast crisis common to CGL in either peripheral blood or bone marrow.
Intrathecal injection of cytosine arabinoside successfully induced remission. In February 1978, she again developed ALL which was again brought to complete remission with vincristin and prednisolone.
Surface marker studies of blasts in cerebrospinal fluid during her meningeal leukemia revealed E rosettes of 55% and EAC rosettes of 30%.
Those in venous blood during her hematological relapse as ALL indicated null cell type.
The terminal deoxynucleotidyl transferase activity during the ALL relapse showed a moderately high level.
It was speculated that this was a case of CGL presenting transient lymphoblastic conversion twice during the clinical course.
