Abstract: FR-PO676
A Case of ANCA-Associated Glomerulonephritis Accompanied by Membranous Lesions During the Course of Recurrent Renal Cancer
Session Information
- Electrolytes and Cancer Trainee Case Reports
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1500 Onco-Nephrology
Authors
- Uchida, Hiroko, Kyorin University School of Medicine, Mitaka, ToKyo, Japan
- Karube, Miho, Kyorin University School of Medicine, Mitaka, ToKyo, Japan
- Kawashima, Soko, Kyorin University School of Medicine, Mitaka, ToKyo, Japan
- Komagata, Yoshinori, Kyorin University School of Medicine, Mitaka, ToKyo, Japan
- Kaname, Shinya, Kyorin University School of Medicine, Mitaka, ToKyo, Japan
Group or Team Name
- Division of Nephrology and Rheumatology
Introduction
ANCA-associated glomerulonephritis (ANCA-GN) has been classified as a pauci-immune type of crescentic glomerulonephritis since glomerular immune complex deposits are not demonstrable by immunofluorescent study and electron microscopy. ANCA-GN and membranous nephropathy (MN) has been rarely reported. We report an ANCA-GN accompanied by membranous lesions during the course of recurrent renal cancer.
Case Description
A 70-year-old male was referred to our hospital because of worsening renal function and persistent hematuria and proteinuria of around 0.5-1 g/gCr. He had underwent left nephrectomy for renal cancer at the age of 49 and also left lung cancer at 60 years. Laboratory examination revealed positive MPO-ANCA titers in the serum (148.4 U/ml) and an elevated serum creatinine level (1.5 mg/dl). There were no other findings that suggest organ involvement of systemic vasculitis. CT and PET-CT scans revealed nodular lesions of the right lower lung and mediastinal mass suspected of malignancy. A renal biopsy revealed necrotizing extracapillary proliferative glomerulonephritis with fibrocellular crescents, compatible with ANCA-associated glomerulonephritis (ANCA-GN). However, immunofluorescent study showed granular depositions of IgG along the glomerular capillary walls, with IgG subclass being positive for IgG1, weak positive for IgG2 and negative for IgG3 and IgG4, suggesting secondary membranous nephropathy. Interestingly, electron microscopy showed deposits along glomerular basement membranes and also paramesangial areas. There were few deposits in the subepithelial areas. He was finally diagnosed with metastatic renal cancer to the lymph node of the mediastinum and chemotherapy with sunitinib was begun. Thereafter, the serum creatinine did not change and MPO-ANCA decreased to 32.6 U/ml without using corticosteroids.
Discussion
Although ANCA-GN accompanied by MN has been rarely reported, the present case showed atypical membranous lesions suggesting unique etiology of immune complex formation.