A case of cardiac dysfunction associated with monoclonal gammopathy of undetermined significance.

The monoclonal gammopathies (MG) are monoclonal neoplasms related to each other by virtue of their development from common progenitors in the B lymphocyte lineage. Cardiac dysfunction in patients with MG is not well established. We experienced a case of cardiac dysfunction associated with MG identified by echocardiography and biopsy. Fifty nine year-old man was admitted because of dyspnea for several months. Echocardiography revealed diastolic dysfunction showing restrictive physiology with elevated left ventricular filling pressure. Bone marrow (BM) studies and immunoelectrophoresis were compatible with monoclonal gammopathy of undetermined significance. Endomyocardial, BM, and enteral biopsies for ruling out for amyloidosis (Congo-red stain) were negative. This is the case of non-amyloidotic light chain deposition cardiomyopathy.