Kidney injury can be a complication of hematopoietic neoplasia by both direct and indirect mechanisms. Virtually all lymphomas and plasma cell dyscrasias can show kidney involvement, including parenchymal infiltration and by secondary injury. Recently, a unique form of glomerulonephritis with masked monotypic immunoglobulin deposits has been reported, which shows frequent association with hematopoietic neoplasia and a propensity for progressive kidney disease. In many instances, these cases are likely diagnosed as glomerulonephritis with dominant C3 due to the absence of immunoglobulin staining by routine immunofluorescence microscopy.