Abstract: FR-PO177
Looking Beyond the Proteinuria
Session Information
- Onconephrology: Clinical and Research Advances - I
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Authors
- Kring, Lauren, Carilion Clinic, Roanoke, Virginia, United States
- Hasan, Alia, VA Medical Center Salem, Salem, Virginia, United States
Introduction
Nephrotic syndrome usually raises concern for primary renal disorders such as membranous nephropathy, focal segmental glomerulosclerosis or minimal change disease. A careful history however, must be taken to evaluate for possible malignancy, especially in a patient with normal GFR. Here we present a case of nephrotic syndrome with normal renal function in whom malignancy was initially overlooked.
Case Description
A 64 year old white male with history of controlled hypertension and new onset diabetes mellitus, presented with leg swelling and was diagnosed with an acute left leg DVT. The edema also prompted his physician to order a 24-hour urine which showed 18g of proteinuria. Referral was made to Nephrology. He endorsed a 16 pound weight loss, “foamy” urine, right hand and left leg neuropathy for the past 2-3 months. He attributed his neuropathy to diabetes.
Labs revealed Hgb 12.1 g/dL, serum creatinine 0.7 mg/dL, albumin 2.9g/dL. Anemia noted for past 4 months. He had mild proteinuria on urinalysis for about 1 year, which worsened 2 months prior; quantification not performed. Hgb A1c was under 6.5. Hepatitis B and C, ANA, dsDNA were negative. Serum protein electrophoresis, immunofixation, and free light chain ratio of 0.67 indicated monoclonal lambda proliferation.
Renal biopsy contained 11 glomeruli: 1 globally sclerotic, others normal on light microscopy. Electron microscopy showed a normal basement membrane with 70% foot process effacement. CT imaging had multiple lytic bone lesions and bone marrow biopsy showed 85% plasma cells. He was diagnosed with multiple myeloma (MM) and started on pulse dose steroids, daratumumab (anti CD38) and RVD (lenalidomide, bortezomib, dexamethasone).
Discussion
While this patient’s nephrotic syndrome was concerning for intrinsic renal disease, he also had new anemia, weight loss, asymmetric peripheral neuropathy and new DVT over a span of 4 months, concerning for underlying malignancy. Light microscopy findings on renal biopsy were consistent with minimal change disease (MCD). MCD is usually associated with hematologic or solid malignancies, but can occasionally be seen in MM. His renal disease therefore was secondary and malignancy related. After starting MM treatment, his proteinuria, edema and neuropathy resolved. This case illustrates the need to assess the patient as a whole and not just focus on one organ or syndrome.