Light chain deposition disease presenting as an atrial mass: a case report and review of literature.

Light chain deposition disease (LCDD) also known as nonamyloidotic immunoglobulin deposition disease is a rare systemic disorder due to the abnormal deposition of immunoglobulin in multiple organs caused by the clonal proliferation of B lymphocytes and plasma cells. Renal involvement is the most common with cardiac manifestations being the most common extra renal presentation of the disease. Renal involvement is not always associated with LCDD. Isolated cardiac involvement can manifest in a wide variety of ways: heart failure, cardiomyopathy, arrhythmias, angina, myocardial infarction, etc. We hereby present an unusual case of 59-year-old female who presented to clinic for routine follow up. A murmur on physical exam was evaluated with echocardiogram which led to the discovery of an incidental right atrial mass. Cardiac magnetic resonance imaging was completed 6 months later for follow up which showed increasing size of the mass. The mass was excised and found to be consistent with LCDD. To the best of our knowledge, this is the first reported case of LCDD manifesting as an atrial mass. Through this case report and review of literature we would like to generate awareness among our fellow pathologists and clinicians to maintain a high level of suspicion for LCDD as it can manifest in many unusual ways, with or without kidney involvement.