Introduction Neoplasia of mature myeloid cells login to view 1 more bullet Most commonly seen in older adults (5th/6th decade) Result of a JAK2 kinase mutation Megakaryocyte hyperplasia results in fibrotic obliteration of the bone marrow login to view 1 more bullet Presentation Symptoms login to view 6 more bullets Evaluation Peripheral blood smear login to view 4 more bullets