Thrombosis Associated with Primary Myelofibrosis

Although primary myelofibrosis (PMF) is usually associated with cytopenias, this entity is classified as a myeloproliferative disorder because it is associated with increased marrow fibrosis and splenomegaly. Thrombosis is also characteristic of myeloproliferative disorders, but whether this is a cardinal feature of PMF is uncertain because of the relative rarity of PMF.

To address this uncertainty, investigators at four European institutions recorded all thrombotic events that occurred in patients with PMF. At a median follow-up of 2.9 years in 707 patients, 7.2% experienced thrombotic events, with incidence divided almost evenly between arterial thromboses (such as strokes, transient ischemic attacks, myocardial infarctions) and venous thr…