Essential Thrombocytosis with CALR/MPL Mutation Presenting as Stroke: Expanding the Limits of Current Risk Stratification (P1-5.006)

Essential thrombocytosis (ET) is a chronic myeloproliferative neoplasm associated with arterial thrombotic events, including ischemic stroke. Mutations in JAK2, CALR, and MPL define distinct vascular risk profiles: JAK2 confers the highest thrombotic risk, CALR (especially type 2) is associated with lower rates, and MPL remains high-risk. Concurrent CALR and MPL mutations are exceedingly rare, and their vascular implications are not well characterized.