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Abstract: SA-PO206

Nephrotic Syndrome with Monoclonal Gammopathy of Undetermined Significance (MGUS): A Case Report

Session Information

Category: Onconephrology

  • 1700 Onconephrology


  • Kim, Chae Won, Gangnam Severance Hospital, Seoul, Korea (the Republic of)

Nephrotic syndrome is characterized by proteinuria, edema, hypoalbuminemia, and hyperlipidemia. A diverse range of disorders has been associated with nephrotic syndrome. Causes of the nephrotic syndrome vary and it can show a vigorous expression of medical conditions. Therefore, it is necessary to establish and treat the etiology of nephrotic syndrome. Differential diagnosis for nephrotic syndrome is challenging due to possibility of nephrotic-range proteinuria by monoclonal gammopathy of undetermined significance (MGUS). Following is a case of a 60-year-old male diagnosed with MGUS concomitant with nephrotic syndrome.

Case Description

A 60-old-male was hospitalized in the nephrology division due to proteinuria, microscopic hematuria, edema in his both ankles and decreased renal function. To rule out glomerulonephritis, blood tests, urinanalysis, kidney biopsy, serum protein electrophoresis (EP), random urine protein EP and immune fixation EP were performed. Blood test results revealed hypoalbuminemia and dyslipidemia. Initial urinary protein-to-creatinine ratio (UPCR) level was 12.5 g/gCr. In the serum protein EP, the M protein was 0.2g/dL, and in the urine protein EP, Bence-Jones proteinuria was detected. The kidney biopsy revealed positive staining for ihC-CD68 in intraglomerular histiocytes; a high possibility of histiocytic glomerulopathy. As this condition has been reported to be associated with underlying hematologic diseases, we requested a consultation with the hematology department for further evaluation. The hematologist performed a bone marrow examination to differentiate between MGUS and myeloma, and to determine the percentage of plasma cells. On bone marrow examination, plasma cells constitute 4.7% of the nucleated cells on aspirate smears. Additionally, a PET scan did not reveal any evidence of primary malignancy or distant metastasis. The patient was diagnosed with MGUS as M protein level was less than 3g/dL, plasma cell ratio was less than 10%, and there were no accompanying myeloma symptoms. Furthermore, it was confirmed that there were no treatable diseases associated with histiocyte-related malignancy or plasma cell disorders.


This case showed that MGUS might be a rare cause of nephrotic syndrome and thorough differential diagnosis for myeloma could be necessary to ensure not to miss the optimal treatment timing.