Multiple Myeloma With a Rare Presentation at Preserved Uninvolved Immunoglobulins

Multiple myeloma is a neoplastic disease of plasma cells that produces monoclonal immunoglobulins, known as monoclonal proteins, causing hypercalcemia, anemia, renal insufficiency, bone lesion, and other organ damage. In most multiple myeloma, the amount of monoclonal protein correlates with the tumor burden and reflects its prognosis. Uninvolved immunoglobulins are often suppressed as monoclonal protein levels increase as a result of the increasing percentage of myeloma cells in the bone marrow. Detection of monoclonal protein by protein electrophoresis, immunofixation, and serum-free light chain assay is a highly sensitive analysis and is not suitable as a screening test because it is positive in a few percent of healthy elderly people, the majority of whom are classified as benign monoclonal gammopathy of undetermined significance. Therefore, it is widely used in practice to measure quantitation of immunoglobulins by nephelometer, and only when uninvolved immunoglobulins are decreasing in the values for each subtype, monoclonal protein identification by immunofixation, serum-free light chain assay, and bone marrow examination must be additionally performed for proactively diagnosing multiple myeloma. However, we experienced symptomatic multiple myeloma in which uninvolved immunoglobulins were not suppressed and there were no significant changes in immunoglobulin levels despite the relatively rapid progression. It would suggest that if you suspect symptomatic myeloma, you should not rule out the possibility of multiple myeloma because of preserved uninvolved immunoglobulins in laboratory findings.