Abstract
Light chain disease is a variant of multiple myeloma in which the malignant population of marrow cells produces free monoclonal light chains but no heavy chain or complete immunoglobulin. The monoclonal light chains are small enough to be freely filtered by the kidneys and become Bence–Jones protein. Light chain disease comprises about 18% of multiple myeloma patients. Here we present a case report of a 38-year-old man who initially presented with complaints of pain in back and low grade fever off and on. He was found to have collapse of D9 and D12 vertebrae along with ascites and right pleural effusion and massive proteinuria. Multiple myeloma was considered as a differential diagnosis based on the investigations but eventually the patient was lost to follow up. This case is reported here as the light chain variant of multiple myeloma leading to deposition disease is less commonly reported and presents considerable difficulties in diagnosis.