A Rare Case of Renal Thrombotic Microangiopathy and Focal Segmental Glomerulosclerosis Secondary to Plasma Cell Leukemia.

Plasma cell dyscrasias are a subset of hematological malignancies involving the production of monoclonal immunoglobulins. This spectrum of disorders includes asymptomatic conditions such as monoclonal gammopathy of unknown significance as well as extremely aggressive malignancies such as plasma cell leukemia. Monoclonal gammopathies are occasionally associated with renal failure, which can occur via many pathophysiological processes. The most common of these is light chain cast nephropathy, but many rare renal complications exist, including thrombotic microangiopathy (TMA) and focal segmental glomerulosclerosis (FSGS). Here, we report a patient with new renal failure with features of TMA and FSGS on biopsy and found to be secondary to plasma cell leukemia.