A Rare Coexistence of Multiple Myeloma and Polycythemia Vera.

Multiple myeloma (MM) is classically associated with organ dysfunction leading to hypercalcemia, renal insufficiency, anemia and bone disease, known as the CRAB criteria. More than 70% of patients with MM present with anemia. Few rare case reports, however, have demonstrated the presentation of MM associated with polycythemia. We present an interesting case of a 65-year-old female who was initially diagnosed with monoclonal gammopathy of undetermined significance (MGUS) which progressed to smoldering myeloma and later developed into MM. The patient also had coexisting polycythemia vera (PCV). We discuss the typical patient presentations as well as the expanded diagnostic criteria for MM. The pathophysiology explaining the coexistence of polycythemia and MM will be explored as well.