A Case Report of Cronkhite-Canada Syndrome Complicated by Membranous Nephropathy

The document reported a case of a 70-year-old man with Cronkhite-Canada Syndrome (CCS) complicated by membranous nephropathy (MN). CCS is a rare disease characterized by gastrointestinal polyposis, alopecia, skin hyperpigmentation, and onychodystrophy. The patient presented with symptoms like diarrhea, weight loss, and hair loss, and later developed nephrotic syndrome. Initial treatments with prednisone, azathioprine, and cyclosporine led to moderate improvement in CCS symptoms but not in proteinuria. The addition of rituximab resulted in remission of MN and significant improvement in polyposis and cutaneous symptoms. The case highlighted the importance of considering renal complications in CCS and suggested rituximab as a potential treatment for refractory CCS and associated MN. The patient's condition improved with corticosteroid therapy, emphasizing the role of immunosuppressive treatment.