Membranous nephropathy in a child with crescentic glomerulonephritis: Coincidence or comorbidity?

Rapidly progressive glomerulonephritis (RPGN) is rare syndrome in children, characterized by clinical features of glomerulonephritis and rapid loss of renal function, and is associated with crescentic glomerulonephritis. Primary membranous nephropathy (MN) is an immune-complex-mediated cause of the adult nephrotic syndrome but occurs less frequently in children. RPGN is rarely observed in adults with primary MN. In this article, we report a case of MN, which developed during long-term follow-up of previously treated RPGN. Our case may be the first to demonstrate primary MN and crescentic glomerulonephritis in a child. We would like to underline the importance of not dropping the long-term follow-up of cases with primary RPGN (not accompanied by other glomerulonephritis and vasculitis symptoms) who had improved with treatment.