An association between membranoproliferative glomerulonephritis and metastatic colorectal carcinoma: a case report

BACKGROUND Membranoproliferative glomerulonephritis is a common pattern of glomerular injury in monoclonal gammopathy, but has only rarely been associated with solid organ tumors, mainly lung, renal, gastric, breast, and prostate. There have been two reported cases of membranoproliferative glomerulonephritis associated with adenocarcinoma of the colon and rectum, although the association may be coincidental. We report a case where nephrotic syndrome due to membranoproliferative glomerulonephritis developed in a patient with colorectal carcinoma and elucidate some of the pathophysiological mechanisms underpinning this presentation. CASE PRESENTATION A 54-year-old white man with a history of adenocarcinoma of the colon with metastasis to the liver and ureter presented with a 1-week history of bilateral pedal edema, and worsening hypertension and renal function. A renal biopsy confirmed membranoproliferative glomerulonephritis type I. Curative therapy for the malignancy was not possible, so treatment was commenced with prednisolone with consequential biochemical improvement in renal function and proteinuria, although his serum albumin remained low. CONCLUSIONS This case report illustrates an association between membranoproliferative glomerulonephritis and metastatic colorectal carcinoma and adds to the evidence to consider malignancy to be an underlying pathology among newly diagnosed cases of nephrotic syndrome. In the clinical setting, treatment of the underlying malignancy should be first considered in patients with a tumor presenting with kidney disease which is suspected to be paraneoplastic in etiology.