Essential thrombocytosis (ET) falls under the umbrella of myeloproliferative disorders, which also includes chronic myelogenous leukemia, polycythemia vera, and myelofibrosis with myeloid metaplasia. Essential thrombocytosis results from a clonal proliferation of megakaryocites within the bone marrow, leading to an absolute elevation of platelets that can cause both hemorrhagic and thrombotic complications.