We report a case of de novo acute myelogenous leukaemia FAB subtype M1 that presents a cytogenetic complex translocation between chromosomes 7, 9 and 22, producing a 'variant' Philadelphia chromosome. Molecular analysis revealed a BCR-ABL rearrangement involving exons b3 and a2 (b3a2). Haematological parameters and genetic analysis again raise the problem of the true nature of this disease, which is briefly discussed.