Extramedullary Myeloma in the era of novel agents report of a case

Multiple myeloma (MM) is a malignant B-cell disorder characterized by a monoclonal expansion of plasma cells (PC) predominantly in the bone marrow (BM). During the main course of disease evolution, MM cells depend on the BM microenvironment for their growth and survival. Reciprocal interactions between MM cells and the BM not only mediate MM cell growth, but also protect them against apoptosis and cause bone disease and angiogenesis.
At diagnosis, extramedullary (EM) disease manifestation is a rare event, but the frequency increases with disease progression. At the end stage of disease, MM cells are thought to develop autocrine growth supporting loops that enable them to survive and to proliferate in the absence of the BM microenvironment and to become stroma-independent. We report a case of EM MM in a patient with advanced MM. A 65-year old female with relapsed and refractory IgG lambda MM, heavily pretreated with Thalidomide, Bortezomib and Lenalidomide was admitted with fever and dyspnea. Chest X-ray showed bilateral lung consolidation, consistent with pneumoniae and broad-spectrum antibiotics were started. Subsequently, her respiratory condition worsened and a chest CT scan revealed massive bilateral pleural effusion. Thoracocentesis was performed for symptom relieve and microbiological analysis. Morphological staining showed the presence of >80% atypical PC. Immunophenotypic evaluation demonstrated a monoclonal population PC expressing IgG lambda. She rapidly generally deteriorated and comfort treatment was given until death 2 days later. MM-related pleural effusion represents a rare form of EM MM and is associated with poor survival, especially when it occurs late in the disease course. It has been observed that the incidence of EM MM increased in the era of new agents. This increase seems however not to be mediated by prior exposure to novel agents, but probably due to the prolongation of patients survival. This case highlights the importance that EM disease manifestation must be suspected in every MM patient with advanced disease.