Objective: To analyse the features of 8 cases of Bcr(+) thrombocytosis.
Methods: The clinical and hematological features and therapeutic outcomes were studied retrospectively in 8 Bcr(+) thrombocytosis and compared with essential thrombocytosis (ET) and chronic myeloid leukemia-chronic phase thrombocytosis (CML-CP-T). BCR-ABL fusion gene was detected with PCR.
Results: (1) Except for the presence of BCR-ABL fusion gene, there was no significant difference in clinical and hematological features and therapeutic outcomes between thrombocytosis with or without BCR-ABL. (2) The Bcr(+) thrombocytosis differed from CML-CP-T in the following aspects: female predominance, milder or no splenomegaly, peripheral leukocytes count < 40 x 10(9)/L, less or no basophilia and fewer immature granulocytes in peripheral blood, bone marrow granulocytic and/or megakaryocytic lineage hyperplasia, normal or increased neutrophil alkaline phosphatase score and less blastic transformation.
Conclusion: Bcr(+) thrombocytosis may be considered as a new member of chronic myeloproliferative diseases, a variant of essential thrombocythemia.