Abstract: TH-PO0197
Neural Epidermal Growth Factor-Like 1 (NELL-1)-Positive Membranous Nephropathy Secondary to Thymoma
Session Information
- Onconephrology: Anticancer Therapies, PTLD, Paraneoplastic Diseases, and More
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Gutierrez, Jorge, Weill Cornell Medicine, New York, New York, United States
- Yang, Yihe, Weill Cornell Medicine, New York, New York, United States
- Glezerman, Ilya, Memorial Sloan Kettering Cancer Center, New York, New York, United States
Introduction
Thymoma is a rare tumor frequently associated with autoimmune paraneoplastic syndromes including myasthenia gravis, SLE, red cell aplasia and thyroid disorders. Paraneoplastic nephropathy is rare in patients with thymoma. We present a case of Neural Epidermal Growth Factor-like 1 positive membranous nephropathy secondary to thymoma.
Case Description
A 52 year-old female with history of hypertension and thymoma type B2/B3 stage IVa treated with definitive radiotherapy 5 months ago was referred for proteinuria. She reported 4 months of bilateral lower extremity edema and weight gain. She has been taking NSAIDs daily, atorvastatin, furosemide and metoprolol but denied any other new medications, herbal supplements or infections. Vital signs were stable and physical exam notable only for pitting bilateral lower extremity edema. On laboratory tests creatinine level 1 mg/dL (0.6 – 1.1 mg/dL), hypoalbuminemia, hypercholesterolemia , complement within normal limits, ANA 1:640, PLA2R Ab negative, THSD7A Ab negative, urinary prot/cr 9 gr/dL and 4-10 RBC/HPF. Renal biopsy revealed immune complex mediated glomerulopathy with membranous pattern of glomerular injury with negative THSD7A and positive NELL-1 stain. Patient started on losartan.
Discussion
In the largest case series of thymoma induced renal disease with 21 patients, only 4 had membranous nephropathy and the majority presented minimal change disease. Two of these cases were type B3 thymoma like our patient.. One of them was male sex, stage IV, associated with red cell aplasia, and MN manifested 5 years after his diagnosis of thymoma and the other was female, stage III, without associated disease, and MN appeared at the time of diagnosis. NELL-1 has been associated with secondary MN due to malignancies. In a report of 91 cases of NELL-1 positive MN thirty patients had a malignancy but only one patient in that cohort had thymoma. We report a second case of NELL-1 positive MN in thymoma patient.