Multiple myeloma is a cancer of plasma cells. The disease most frequently occurs in the marrow of large bones, such as the skull, pelvis and vertebra. In this disease the malignant cells form tumors which can prevent the marrow from producing healthy red, white and platelet blood cells. Because plasma cells travel through the body, tumors often occur in several sites simultaneously. Approximately 15,000 people in the United States are diagnosed with multiple myeloma every year. Multiple Myeloma Risk Factors Multiple Myeloma Warning Signs Multiple Myeloma Detection, Diagnosis and Staging Multiple Myeloma Treatment Other Links: Stem Cells Stem Cell Transplant / Bone Marrow Transplant Transplant Candidates What Are Stem Cells? The Stem Cell Transplant Process The Stem Cell Transplant Team Download Patient Handbook (PDF) Frequently Asked Questions Contact Us