Nephrotic syndrome associated with fibrillary deposits in the glomeruli

A 48-year-old woman with nephrotic syndrome underwent renal biopsy. Light microscopy showed nodular sclerosis and thickening of the glomerular capillary wall. Immunoglobulins (Ig) G, especially IgG2, IgM, IgA, C3, C1q were detected along the glomerular capillary walls by immunofluorescent microscopy. Electron microscopy revealed that fibrillar materials of about 25 nm were accumulated in the subepithelial area of the glomerular basement membrane. These materials were negative for Congo-red staining. Neither cryoglobulinemia nor paraproteinemia including light chains was found. This case was diagnosed as membranous nephropathy by clinical findings and pathological examinations, and seemed to be a case of fibrillary glomerulonephritis.