Myeloproliferative disorders (MPDs), also identified by the World Health Organization (WHO) as myeloproliferative neoplasms (MPNs), are considered clonal stem cell disorders that lead to an overproduction of blood cells in the myeloid line. Disorders of the myeloid cell lines lead to conditions such as polycythemia vera (PV), essential thrombocytosis (ET), primary myelofibrosis (PMF), and chronic myelogenous leukemia (CML). MPDs and myelodysplastic syndrome (MDS) represent a spectrum of clonal conditions in which genetic mutations lead to an abnormally regulated proliferation of hematopoietic progenitors. MPDs are identified primarily through morphologic assessment of bone marrow cells, aspirate, and peripheral blood evaluation. MPDs and myelodysplastic disorders may have the functional caveat of producing extramedullary hematopoietic (EMH) tissue when the liver and spleen launch into hematopoietic production in a proliferative and disordered state. Patients with myeloproliferative or myelodysplastic disorders have many diverse presentations and courses of their illness.