The majority of patients with myeloma develop destructive bone lesions, also known as osteolytic bone lesions. These lesions occur primarily in the vertebrae, the ribs, the pelvis, and the skull. They occur in the red bone marrow where nests of myeloma cells accumulate.
Plasma cells produce antibodies to help fight infection and disease.
In multiple myeloma, cancerous plasma cells are found in the bone marrow, the spongy tissue inside of bones that manufactures the different types of blood cells. The abnormal plasma cells produced in the bone marrow are called myeloma cells. When myeloma cells accumulate in the bones, they can cause many tumors that damage and weaken bones. Normal plasma cells are an important part of the immune system. The immune system is composed of several types of cells that work together to fight off infections and other diseases.