Myeloperoxidase antineutrophil cytoplasmic antibody-positive necrotizing crescentic glomerulonephritis and membranous glomerulonephropathy.

In September 1997, a 68-year-old woman was found to have proteinuria and renal dysfunction. In December 1997, renal biopsy revealed necrotizing crescentic glomerulonephritis and membranous glomerulonephropathy. We diagnosed myeloperoxidase antineutrophil cytoplasmic antibody-positive necrotizing crescentic glomerulonephritis and membranous glomerulonephropathy because of the presence of necrotizing cellular crescents and spike lesions in the subepithelial region of the glomerular basement membrane. After steroid therapy, the antibody level and the incidence of cellular crescents showed a decrease. This is a rare case of myeloperoxidase antineutrophil cytoplasmic antibody-positive necrotizing crescentic glomerulonephritis associated with membranous glomerulonephropathy.