Amyloidosis-Related Cardiomyopathy Revealing Waldenstrom Macroglobulinemia: A Case Report.

Cardiac amyloidosis is a rare infiltrative disease caused by the deposition of extracellular insoluble aggregates of misfolded proteins. Most cardiac amyloidosis seen in the clinic is due to either amyloid light-chain (AL) of immunoglobulins or transthyretin accumulation in various cardiac structures. AL amyloidosis is most often secondary to a monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma. More rarely, it is associated with lymphoplasmacytic lymphoma, a low-grade, mature, B-cell non-Hodgkin lymphoma. Here, we present a rare case of cardiac AL amyloidosis caused by Waldenstrom macroglobulinemia in a 70-year-old man. The clinical and biological characteristics of the patient, as well as the mutational profile, are detailed and discussed. This case report sheds light on the rare association of AL amyloidosis and Waldenstrom macroglobulinemia. It underlines the importance of the multidisciplinary collaboration between cardiologists, hematologists, clinical pathologists, and amyloidosis specialists to overcome diagnostic challenges using specific key tools encompassing immunofixation electrophoresis, mass spectrometry, immunophenotyping, cardiac magnetic resonance imaging, and next-generation sequencing. All of the above lead to the establishment of an early and appropriate diagnosis of such a rare clinical association, thus optimizing patient management.