Atypical Ph-negative chronic myeloid leukemia (CML) with an acute lymphoblastic leukemia onset and a variant BCR-ABL transcript (b3-a3 junction).

An atypical case of Ph-negative chronic myeloid leukemia with an acute lymphoblastic leukemia onset and a variant BCR-ABL transcript (b3-a3 junction) is reported. RT-PCR was falsely negative and diagnosis was based upon FISH technique. This molecular variant was characterised by unusual clinical features prolonged benign course, marked platelet sensitivity to interferon alpha and important cyclic hyperleukocytosis. [ABSTRACT FROM AUTHOR]