Polycythemia vera
A myeloprolifeartive neoplasm that usually carries the JAK2 mutation. Patients with this neoplasm typically present with splenomegaly, and some "cytosis" which is usually in the form of an elevated hematrocrit/hemoglobin with low EPO levels. The bone marrow is usually hypercellular similar to many of the other myeloproliferative neoplasms.