Molecular Features and Clinical Outcomes of Extramedullary Plasmacytomas

The treatment of multiple myeloma (MM) continues to evolve with new drugs, resulting in dramatically improved outcomes. Despite these advances, MM remains an incurable disease, with Extraosseous/Extramedullary disease (EMD) playing a major role in the development of relapsed refractory disease. EMD is defined by the development of plasma cell neoplasms that arise in tissues other than bones. EMD can present at diagnosis or develop during the disease course of MM. Sometimes EMD can be solitary without bone marrow (BM) involvement. Determining the molecular underpinnings of EMD are critical to advance the care of such patients. A few reports suggest a possible role of Ras mutations in the intramedullary to extramedullary transition in a limited number of patients. Therefore, the molecular biology of developing EMD has not yet been clearly defined.