Kidney Week

Abstract: FR-PO0789

A Tale of Two Glomerulopathies: Membranous Nephropathy with ANCA-Associated Vasculitis in a Patient with Lung Adenocarcinoma

Session Information

• Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Ijaz, Zara, Houston Methodist Hospital, Houston, Texas, United States

Zara Ijaz, MD

• Farooqui, Ozer A., Houston Methodist Hospital, Houston, Texas, United States

Ozer A. Farooqui, MD

• Deshpande, Yash, Houston Methodist Hospital, Houston, Texas, United States

Yash Deshpande, MD

• Iqbal, Qura Tul Ain, Houston Methodist Hospital, Houston, Texas, United States

Qura Tul Ain Iqbal, MD

• Edwards, Angelina, Houston Methodist Hospital, Houston, Texas, United States

Angelina Edwards, MD, FASN

• Adrogue, Horacio E., Houston Methodist Hospital, Houston, Texas, United States

Horacio E. Adrogue, MD, FASN

• El-Zaatari, Ziad M., Houston Methodist Hospital, Houston, Texas, United States

Ziad M. El-Zaatari

Introduction

Membranous nephropathy (MN) is the most common glomerular lesion linked to solid organ malignancy, marked by subepithelial immune complex deposition and glomerular basement membrane thickening. Although phospholipase A2 receptor (PLA2R) positivity is classically associated with primary MN, emerging evidence shows that PLA2R-associated disease may also occur in the setting of malignancy. Recent literature suggests that patients with PLA2R-associated MN are at higher cancer risk compared to the general population, particularly among smokers. Concurrent overlap with ANCA-associated crescentic glomerulonephritis (GN) is rare and clinically aggressive. In contrast to MN, ANCA-associated crescentic GN is characterized by pauci-immune necrotizing crescentic GN, driven by neutrophil activation against myeloperoxidase (MPO) or proteinase-3 (PR-3).

Case Description

A 79-year-old female with a 37-pack year smoking history and prior left breast cancer treated with radiation, chemotherapy, and eventual mastectomy presented with acute progressive painful binocular diplopia. Clinical evaluation revealed orbital and cavernous sinus inflammation mimicking Tolosa-Hunt syndrome, but prompt imaging and systemic workup identified multifocal pulmonary nodules. Concurrently, the patient developed nephrotic range proteinuria (UPCR 6556 mg/g and 24-hour urine protein 8160 mg/g). Her serologic workup was positive for MPO antibodies. Screening for lupus, Sjogren’s syndrome, ANCA, and PR-3 was negative. Complement levels were preserved, and immunoglobulin subclass testing was unremarkable. Subsequent renal biopsy demonstrated PLA2R-positive MN with superimposed pauci-immune crescentic GN with early crescent formation. Lung biopsy revealed KRAS-positive lung adenocarcinoma. PET scan showed no metastatic disease. Treatment focused on addressing the newly diagnosed lung cancer while concomitantly silencing the MN with rituximab. Here, we present a rare case of PLA2R-positive MN with concurrent MPO-ANCA crescentic GN in the setting of underlying lung adenocarcinoma.

Discussion

Patients with PLA2R-associated MN have an increased cancer risk, particularly smokers. Overlap with ANCA-associated crescentic GN is rare and aggressive. This case highlights concurrent PLA2R-positive MN and MPO-ANCA crescentic GN in a patient with lung adenocarcinoma, significant smoking history, and prior breast cancer.

Acknowledgment

The authors would like to acknowledge the departments of Nephrology, Rheumatology, Pathology, and Oncology at Houston Methodist Hospital for their contributions to this case.