A Rare Case of Coexisting Multiple Myeloma and Renal Cell Carcinoma

Document Type

Conference Proceeding

Publication Date

4-2025

Publication Title

American Journal of Kidney Diseases

Abstract

n the U.S. is approximately 1 in 132 (1). Renal cell carcinoma (RCC), arising from renal parenchymal cells, affects about 80,000 individuals annually in the U.S. (2). Although MM and RCC rarely co-occur, recent observations suggest a potential association. Here, we present a unique case of simultaneous MM and RCC. An 82-year-old male with a history of prostate cancer in remission, anemia, and hypertension presented with oliguria and bilateral lower extremity swelling. Initial labs revealed creatinine of 3.3 mg/dL, indicating acute kidney injury, and he was admitted for suspected acute tubular necrosis (ATN). Bi-cytopenia was also noted. Abdominal CT showed progression of a left renal mass from prior imaging and a new right renal mass. Nephrology initiated hemodialysis. Anemia evaluation included unremarkable esophagogastroduodenoscopy and colonoscopy. Further workup and iron deficiency anemia, with no evidence of hemolysis. Vasculitis, rheumatologic workup, B12 and folate levels were normal. Serum and urine electrophoresis showed a questionable free lambda band, and the urine protein-to-creatinine ratio was slightly elevated at 0.14. Renal duplex was unremarkable. Bone marrow biopsy confirmed multiple myeloma (MM) with 17.4% plasma cells. Renal biopsy revealed myeloid kidney and an incidental right renal cell carcinoma. Pan-CT and skeletal survey ruled out metastasis. Treatment for MM was initiated with CyBorD, and hemodialysis was scheduled thrice weekly for ATN. The patient was not a candidate for plasmapheresis, surgery, or cryoablation. In RCC, multiple primary malignancies, including prostate, bladder, and non-Hodgkin's lymphoma, have been reported. Certain cytokines, such as IL-6, are elevated in RCC patients and stimulate myeloma cells. Additionally, shared risk factors include hypertension, obesity, and smoking. This case helps raise awareness of the RCC-MM association and prompts further investigation for MM in patients with RCC when new osteolytic lesions are identified on a bone scan.

Volume

85

Issue

4 Suppl 1

First Page

S15

Comments

National Kidney Foundation 2025 Spring Clinical Meeting, April 9-13, 2025, Boston, MA

Last Page

S15

DOI

10.1053/j.ajkd.2025.02.044

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