title: Atypical Plasmacytic Proliferation in a Case of C3 Glomerulopathy: Pathophysiology Demystified.
abstract: An 11-year-old Hispanic female underwent evaluation of asymptomatic proteinuria and hematuria. The patient denied fever, edema, and gross hematuria. Urinalysis showed mild proteinuria, and a urine microscopic examination revealed red blood cells. Screening tests for glomerulonephritis revealed a low C3 and negative ANA, ASO, DNAse-B, and ANCA. Histological examination of a renal biopsy specimen showed glomeruli with endocapillary proliferation, a predominant C3 deposition in the capillary loops by immunofluorescence, and electron dense deposits in the mesangium, paramesangium, and capillary walls by electron microscopy consistent with a diagnosis of C3 glomerulopathy. An interstitial plasmacytosis was also present with focal clustering of plasma cells, which were found to be kappa light chain restricted by in situ hybridization suggestive of a clonal proliferation. One can speculate that these plasma cells may be directly responsible for the renal pathology that was seen.
authors.affiliation: Department of Pathology, University of Illinois, Chicago, IL, USA.
authors.forename: Osama
authors.initials: O
authors.lastname: Elfituri
authors.affiliation: Department of Pathology, University of Illinois, Chicago, IL, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Aardsma
authors.affiliation: Department of Pathology, University of Illinois, Chicago, IL, USA.
authors.forename: Suman
authors.initials: S
authors.lastname: Setty
authors.affiliation: Department of Pathology, University of Illinois, Chicago, IL, USA.
authors.forename: Frederick
authors.initials: F
authors.lastname: Behm
authors.affiliation: Department of Pediatrics, University of Illinois, Chicago, IL, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Czech
keywords: C3 glomerulopathy; kidney; monoclonal