Adult Segmental Membranous Nephropathy Presenting As Nephrotic Syndrome: A Rare Case Report and Literature Review

Segmental membranous nephropathy (sMN) is a rare pathological variant of membranous nephropathy (MN). Patients with sMN present with segmental subepithelial granular deposits of IgG in glomeruli. Patients with sMN have diverse clinical manifestations, including proteinuria, nephrotic syndrome, and renal insufficiency. Patients may have sMN secondary to a variety of diseases, such as lupus and tumors. We, herein, reported the case of an adult whose diagnosis of sMN had been confirmed by pathology analysis, but who had clinical manifestations of nephrotic syndrome. In addition, we reviewed the clinical characteristics of 87 adult sMN cases reported in China and other countries and found that sMN in adults might occur separately or the patients may present with other glomerular or tubulointerstitial diseases in conjunction, often overlaying with another major disease process, which suggests that clincians must first rule out secondary renal injury.