Acquired delta-storage pool deficiency associated with idiopathic myelofibrosis

A 73-year-old woman complained of easy bruising, as a consequence of prolonged bleeding time despite normal platelet counts. Platelet aggregation profile, mepacrine fluorescence test, flow cytometry and transmission electron microscopy studies led to the diagnosis of delta-storage pool deficiency (SPD) A few months later, she developed hyperleucocytosis with immature granulocytes and erythroblasts. The presence of bone marrow fibrosis and clonal cytogenetic abnormalities led to the diagnosis of idiopathic myelofibrosis (IM). Association between SPD and IM has never been reported. The pathogenesis of this unusual association remains unclear and may involve proliferation of abnormal monoclonal stem cells with differentiation into activated megakaryocytes associated with impaired dense granule development and increased cytokines release which may be. involved in myelofibrosis.