Myeloma is a malignancy of the plasma cells, which is a type of white blood cell within the bone marrow (the spongy tissue within the bone). Bone marrow is predominantly found in the spine, pelvis, ribs, skull and shoulders.2
Plasma cells are part of the immune system and produce antibodies that help bacteria and other pathogens.2 When plasma cells become malignant, they multiply and spread throughout the bone marrow so that there is less room for healthy cells to develop and grow. 2
Myeloma is often known as multiple myeloma (and occasionally as myelomatosis or plasma cell myeloma) due to the multiple sites of bone marrow lesions found at diagnosis.2