[Chronic myeloid leukemia without Philadelphia chromosome (Ph-negative CML)]

Ph-negative chronic myeloid leukemia [Ph(-)CML] is a heterogenous group of conditions characterized by similar cytogenetic pattern but variable changes at the molecular level. All cases with BCR gene rearrangement in this group have clinical and haematological course similar to Ph(+)CML. However, CML without rearrangements of ABL and BCR genes, called "atypical CML", forms a separate entity showing clinical and morphological features different from classical CML.