Histopathological atlas of renal diseases--IgA nephropathy.

The characteristic and diagnostic lesion of idiopathic IgA nephropathy (IgAN, Berger's disease) is glomerular IgA deposition, as a unique or predominant positive immunoglobulin. Despite the relatively uniform feature of the immunohistological pattern, the morphological lesions observed by light microscopy are extremely variable. This variability in glomerular and interstitial alterations has frequently created some difficulties in histological classification.