Malignant proliferation of plasma cells  overproduction of abnormal antibodies (paraproteins or light-chain protein)
Osteoclasts are activated through the RANK pathway by the abnormal antibodies leading to osteolytic lesions
Symptoms result from accumulation of plasma cells and paraproteins
Most common primary bone malignancy
More commonly seen in African Americans and males
Osteoclasts are activated through the RANK pathway by the abnormal antibodies leading to osteolytic lesions
Multiple myeloma
Hemorrhage
Myelofibrosis
Hereditary
Non-Hodgkin's lymphoma
Acquired
Chronic lymphocytic leukemia
Microangiopathic Hemolytic Anemia 