Abnormal glomerular basement membrane morphology Glomerular basement membrane disruption 2021-01-10T12:39:06Z Disruption of the glomerular basement membrane A point of rupture in the glomerular basement membrane (GBM) where the discontinuous portions of GBM are still identifiable with a basement membrane stain such as Periodic acid Schiff (PAS) or silver. Disruption of the glomerular basement membrane (GBM) may occur in settings of inflammation (ANCA/antiGBM antibodies) or could be seen due to structural weakness of the GBM (Collagen IV disorders). This feature can be associated with extracapillary fibrin. The definition of this term intends to exclude glomeruli at the edge of the core where rupture could be iatrogenic or mechanical. Glomerular basement membrane rupture