megakaryoblastic leukaemiaA rare clonal proliferation of platelet stem cells arising in severe myelofibrosis, which is defined by the presence of 30+% blasts in the bone marrow. It is more common in patients with Down syndrome.
Pallor, weakness, excess bleeding, anaemia, leukopaenia.
Immunocytologic studies of von Willebrand factors and lineage-specific glycoproteins (GPIb, IIb/IIIa or IIIa).
Dismal in the sporadic cases and in children with the translocation t(1;22)(p13;q13); the remaining third of patients (with Down syndrome) have a relatively good prognosis.