nal lesions were systemically reviewed in a large series of renal biopsies ne both in Paris and in Seattle over a period of 15 years. Clinical esentation as well as the renal lesions were assessed. All the renal opsies were examined by light microscopy and immunofluorescence. In dition, electron-microscopy was available in a limited number of cases. omerular lesions were reviewed in lymphomas, leukemias and carcinomas. The equency of proliferative lesions in chronic lymphocytic leukemias has been derestimated: most diffuse glomerular lesions appear to be associated with yoglobulinemias. Twelve cases have been added to those published in the terature.