Abstract: FR-PO1294
Membranous Nephropathy as a Paraneoplastic Manifestation of Periorbital Lymphoma: A Diagnostic Challenge
Session Information
- Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Authors
- St Gilus, Rose H., Stamford Health, Stamford, Connecticut, United States
- Babayev, Revekka, Stamford Health, Stamford, Connecticut, United States
Introduction
Membranous nephropathy (MN) is a common cause of adult nephrotic syndrome and may be primary or secondary to systemic conditions, including malignancy. PLA2R-negative MN should prompt evaluation for secondary etiologies. While solid tumors are most often implicated, hematologic malignancies such as lymphoma are increasingly recognized as causes of paraneoplastic MN. Early identification is critical, as management depends on treating the underlying disease.
Case Description
A 51-year-old man with history of HTN was evaluated for elevated serum creatinine (2.0–2.3 mg/dL) and low-grade proteinuria. Estimated GFR (30–45 mL/min) was discordant with measured 24-hour creatinine clearance (~100 mL/min), attributed to high muscle mass. Urinalysis showed intermittent sterile pyuria and subnephrotic proteinuria. Renal ultrasound was normal, and kidney function remained stable for over two years with proteinuria improving with losartan. His course was notable for chronic leukopenia, mild peripheral eosinophilia, and progressive right eyelid swelling with lacrimal gland enlargement. Sarcoid interstitial nephritis was suspected, which prompted kidney biopsy. Histopathology demonstrated membranous glomerulopathy with negative PLA2R, and other known antigens (including NELL1), mild background IgA deposition, and chronic changes (50% global glomerulosclerosis, 10% interstitial fibrosis/tubular atrophy). There was no tubulointerstitial infiltrate or granulomas to suggest sarcoid. Hepatitis B and RPR were negative. Subsequent evaluation of the peri-orbital lesion revealed lymphoma involving the lacrimal gland and adjacent structures. The MN was attributed to a paraneoplastic manifestation of lymphoma, and chemotherapy was prescribed.
Discussion
This case underscores the importance of evaluating PLA2R-negative MN for secondary causes, particularly malignancy. Extrarenal findings such as lacrimal gland enlargement may provide key diagnostic clues. Recognition of paraneoplastic MN is essential, as treatment of the underlying malignancy is central to management and prognosis.