A Rare Case of Light Chain Myeloma with Amyloidosis

Abstract

Background: Multiple myeloma is characterized by neoplastic proliferation of a single clone of plasma cells producing a monoclonal immunoglobulin. It comprises about 1% of all malignant tumours and 10-15% of haematopoietic neoplasms. Light chain myeloma accounts for up to one-fifth of all cases of myeloma and is typified by only a light chain in the serum or urine, lacking expression of the immunoglobulin heavy chain. Amyloidosis is characterized by extracellular deposition of insoluble fibrillar protein called amyloid, in various tissues and organs. Light chain (LC) amyloidosis is the most common form of systemic amyloidosis and it complicates about 10% of cases of myeloma. When multiple myeloma is complicated by LC amyloidosis, the myeloma is typically diagnosed before or around the time of the diagnosis of amyloidosis. Case presentation: We report a rare case of an elderly patient who presented with constitutional symptoms, anaemia and renal failure with negative myeloma screen who was ultimately diagnosed with light chain myeloma with systemic amyloidosis. Conclusion: This case highlights that it is important to perform a series of clinically directed laboratory investigations to evaluate a suspected case of myeloma even if the routine investigations of myeloma screen are negative. Even though rare light chain myeloma should be thought of in a patient, who has anaemia and renal failure, where the initial myeloma screen is negative.