A rare case of diffuse crescents in fibrillary glomerulonephritis

Diffuse crescentic involvement in fibrillary glomerulonephritis (FGN) is very rare. We describe a case of FGN with dif-fuse crescents in a patient who presented with clinical findings concerning for rapidly progressive kidney failure and pathologic findings suggestive of anti-glomerular base -ment membrane (GBM) disease. Serologies for anti-neutrophil cytoplasmic antibody (ANCA) and anti-GBM were negative. IgG subtyping showed IgG1 dominance, which has not been described in FGN. We present this unique case to emphasize the impor-tance of considering FGN in biopsies show -ing diffuse crescentic glomerulonephritis with linear IgG staining of glomerular capil-lary walls, especially in the absence of other significant proliferative changes.