Glomerular collapse in association with acute cortical necrosis in native kidneys: all that collapses is not idiopathic collapsing glomerulopathy

Glomerular collapse is an essential characteristic of collapsing glomerulopathy (CG), a distinctive proliferative renal parenchymal disease defined by the segmental or global collapse of capillary tufts associated with prominent podocyte hyperplasia and hypertrophy. First described in the mid-1980s as an idiopathic disorder or following human immunodeficiency virus(HIV)-1 infection, it is now associated with a broad range of diseases and different pathogenetic pathways which contribute to the podocyte injury and their aberrant proliferation. Although the association between subtotal infarction and de novo CG in transplanted kidneys has recently been reported, to our knowledge, no such association of this lesion with the acute cortical necrosis (ACN) in the native kidneys has been reported in literature to date. We describe 2 cases of glomerular collapse with typical morphological features of CG occurring in the background of ACN in native kidneys and discuss its possible pathogenesis with reference to the existing literature.