Objective To investigate the pathogenesis of Philadelphia (Ph)-positive acute lymphocytic leukemia (ALL), we established a lymphoblastoid cell line.

Methods Bone marrow cells from a patient with Ph-positive ALL were enriched by Ficoll-Hypaque centrifugation and cultured in medium with fetal calf serum.

Materials The mononuclear cells of bone marrow aspirate were obtained from an adult man with ALL after he experienced relapse following induction therapy including imatinib mesylate.

Results The cell line termed TNA-M was established, carrying a three-way Ph translocation involving two chromosome 9s and one chromosome 22 as a sole karyotypic abnormality. Furthermore, the cells were positive for CD13 and CD33 in addition to CD19, CD22 and CD79a antigens.

Conclusion This unique cell line is expected to be a valuable tool for understanding the pathogenesis of Ph-positive ALL.