title: Glomerulonephritis With Masked Monotypic Immunoglobulin Deposits and Concurrent Lymphomatous Infiltration.
abstract: 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. The patient reported here showed lymphomatous infiltration on kidney biopsy and mesangial proliferative glomerulonephritis with dominant staining for C3 without immunoglobulins on initial immunofluorescence; however, monotypic immunoglobulin G κ light chain was revealed after additional immunofluorescence staining was performed on the paraffin-embedded tissue. This patient's case highlights the evolving state of kidney biopsy interpretation and the expanding spectrum of kidney disease in the setting of hematopoietic neoplasia.
authors.affiliation: Department of Pathology, University of Utah, Salt Lake City, UT.
authors.forename: Isaac E
authors.initials: IE
authors.lastname: Lloyd
authors.affiliation: Department of Pathology, University of Utah, Salt Lake City, UT. Electronic address: mazdak.khalighi@hsc.utah.edu.
authors.forename: Mazdak A
authors.initials: MA
authors.lastname: Khalighi
mesh_terms: D000368:Aged; D005921:Glomerulonephritis / Q000276:immunology* / Q000473:pathology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007145:Immunoglobulin kappa-Chains / Q000276:immunology*; D016246:Lymphocytes, Tumor-Infiltrating; D020522:Lymphoma, Mantle-Cell / Q000150:complications* / Q000473:pathology*; D008297:Male
chemical_list: D007074:Immunoglobulin G; D007145:Immunoglobulin kappa-Chains
keywords: Glomerulonephritis; IgGκ; antigen retrieval; hematopoietic neoplasia; kidney biopsy; lymphomatous infiltration; masked deposits; proteinase predigestion; renal infiltration