Crescentic glomerulonephritis and membranous nephropathy: a rare coexistence

Background The coexistence of crescents and membranous glomerulonephritis (MGN) is a special characteristic in lupus nephritis. In the absence of the characteristic histological features of lupus nephritis, MGN with crescents should raise the possibility of two other histopathological entities: anti-GBM disease and necrotizing and crescentic glomerulonephritis. The last one includes patients with positive ANCA serology or not. Results and conclusions Here, we describe a case of a male patient who presented with extrarenal vasculitis symptoms, acute renal failure, hematuria and nephrotic-range proteinuria. ANCA serology was positive, and the biopsy revealed crescentic vasculitis plus membranous nephropathy. Reviewing the whole literature about similar histological cases, we included 38 cases with ANCA-positive serology and 30 ones with no ANCA in serum. It seems that in the first category vasculitis symptoms predominate, while in the second one these symptoms are absent. Their histological features have no major differences. In any case, the clinical course of these patients is serious, and in most cases, immunosuppression is essential in order to avoid end-stage renal disease.