title: Heterogeneous blast cell crises in Philadelphia negative chronic granulocytic leukaemia.
abstract: A case of Philadelphia negative chronic granulocytic leukaemia (Ph1-CGL) is described showing features only previously demonstrated in Ph1+ disease. These features include: (1) lymphoid blast crisis, determined by morphology and immunological marker analysis; (2) dual blast cell populations that can be distinguished both morphologically and by immunological markers; (3) clonal evolution, as shown by the emergence of chromosome markers and in one of the cell lines a change in membrane phenotype. These changes were apparently associated with the emergence of a relatively drug resistant subclone of leukaemic cells. This study demonstrates that the lymphoid blast crisis of CGL, and its sequelae, can occur in Ph1- cases. It is similar in respect to morphology, enzyme, and membrane markers and responsiveness to vincristine and prednisolone therapy to the lymphoid blast crisis seen in Ph1+ CGL. This suggests that the Philadelphia chromosome is a clonal marker only, and its presence is not directly related to the subsequent clinical course of the disease.
mesh_terms: D001853:Bone Marrow / Q000648:ultrastructure; D002869:Chromosome Aberrations; D002904:Chromosomes, Human, 21-22 and Y; D006801:Humans; D007621:Karyotyping; D007951:Leukemia, Myeloid / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010641:Phenotype