[A case of myelodysplastic syndrome transforming into acute B-cell lymphoid leukemia].

Case history of a seventy year old man with myelodysplastic syndrome is presented. The disease terminated into acute leukaemia in 22 months. The pure, B lymphoid stem cell nature of the leukaemic cells has been proved, beside morphology and cytochemistry, by detailed flow cytometric phenotyping and PCR amplification as well as sequencing of the immunoglobulin heavy chain gene CDR3 region.