Molecular response to imatinib in patient with Ph negative p190 BCR-ABL transcript positive chronic myeloid leukemia with cyclic leukocytosis.

An atypical case of Philadelphia (Ph) negative, e1a2 BCR-ABL transcript positive chronic myeloid leukemia (CML) characterized with cyclic periodic leukocytosis and spontaneous remissions is reported. The patient was treated with imatinib and good hematology response with molecular remission was achieved. So far, only few Ph positive CML patients expressing p190 BCR-ABL protein and different clinical characteristics and treatment have been described in the literature. This is the first report of Philadelphia negative, p190 BCR-ABL positive CML with cyclic spontaneous oscillation of white blood cell count (WBC), and excellent response to imatinib treatment.