Successful treatment with imatinib mesylate of a CML patient in megakaryoblastic crisis with severe fibrosis

Unprecedented Megakaryocytic Blast Phase Transformation in Chronic Myeloid Leukemia After 16 Years of Tyrosine Kinase Inhibitor Therapy

We report the case of a 51-year-old Japanese man with chronic myeloid leukemia (CML) initially diagnosed in the chronic phase. For 16 years, the patient maintained chronic phase (CP) under treatment with first- and second-generation tyrosine kinase inhibitors (TKIs), including imatinib, dasatinib, and bosutinib, none of which resulted in ABL1 mutations. However, despite long-term disease stability, the patient experienced an abrupt progression to the megakaryocytic blast phase (MBP), a rare and aggressive form of CML. In response to this progression, ponatinib, a third-generation TKI, was introduced as a fourth-line therapy. Remarkably, within 7 months of initiating ponatinib, the patient achieved a deep molecular response (DMR), evidenced by a reduction in BCR::ABL1 transcript levels to undetectable levels (MR5.0). This molecular remission enabled the patient to proceed with an allogeneic bone marrow transplantation from a human leukocyte antigen (HLA) 8/8-allele-matched unrelated donor. Post-transplantation, the patient has maintained DMR for 14 months without recurrence, despite the challenges posed by graft-versus-host disease. This case illustrates the critical role of third-generation TKIs like ponatinib in managing advanced CML phases, especially when previous therapies fail. It also emphasizes the necessity of vigilant long-term monitoring during the chronic phase to detect and address any signs of disease progression promptly.

The enigma of pulmonary hypertension after splenectomy--does the megakaryocyte provide a clue?

Pulmonary hypertension is a common and debilitating condition which is increasingly being recognized in haematological patients. This is particularly so in haemolytic diseases like thalassaemia and myeloproliferative conditions like idiopathic myelofibrosis. Recently, splenectomy, which may be required for some of these conditions, have been linked to this complication although the exact pathophysiology is still not established. The manuscript explains the role of the less recognized 'lung megakaryocytes' in the development of this complication.

Co-existence of Philadelphia chromosome positive acute megakaryoblastic and B-lymphoblastic mixed blast crisis of chronic myeloid leukemia with chronic lymphocytic leukemia

In this study, we describe an extremely rare case of co-existence of a Philadelphia chromosome positive acute megakaryoblastic and B-lymphoblastic mixed blast crisis of chronic myeloid leukemia with chronic lymphocytic leukemia. A morphological, immunophenotypical and cytogenetic study has been performed to characterize the case and in order to identify the origin of two disorders. After the failure of the conventional therapy, the patient was treated with Imatinib with a complete hematological and cytogenetic response and a marked reduction of bone marrow fibrosis.