Abstract: TH-PO1112
Renal Lymphomatous Infiltration Mimicking Drug-Induced Acute Interstitial Nephritis
Session Information
- Pathology and Lab Medicine
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1700 Pathology and Lab Medicine
Authors
- Brown, Brittany S., Emory University, Atlanta, Georgia, United States
- Waheed, Sana, Emory University, Atlanta, Georgia, United States
- Jagannathan, Geetha, Emory University, Atlanta, Georgia, United States
- Daswatta, Dilini M., Emory University, Atlanta, Georgia, United States
Introduction
Renal involvement by lymphoma is common histologically but clinically significant kidney injury from lymphomatous infiltration is relatively uncommon and may mimic other causes of acute kidney injury (AKI), including drug-induced acute interstitial nephritis (AIN).
Case Description
29-year-old male with history of hypertension presented with shortness of breath, dyspnea, and cough. CT imaging was notable for large mediastinal mass with retroperitoneal lymph node involvement, large pericardial effusion, bilateral pleural effusions, and poorly enhancing lesions on the left kidney. At presentation, creatinine was 1.0mg/dL, uric acid 8.5mg/dl. Given high suspicion for lymphoma, patient was started on allopurinol for prophylaxis of tumor lysis syndrome. Creatinine began uptrending after admission, peaking to 6.2mg/dL. Urinalysis showed no proteinuria or hematuria and only 2-5 WBCs. A kidney biopsy was performed which showed diffuse interstitial inflammation. Subsequently, the patient was started on steroids with a suspected diagnosis of allopurinol related AIN. Allopurinol was stopped and creatinine started improving. Definite mediastinal mass biopsy confirmed the diagnosis of B cell lymphoma.
Discussion
Renal lymphomatous infiltration may closely mimic AIN both clinically and histologically, particularly in the setting of recent medication exposure. This case highlights the importance of maintaining a high index of suspicion for renal involvement in patients with suspected lymphoma and unexplained AKI, as timely recognition and appropriate immunohistochemical evaluation are critical for accurate diagnosis and management.
Acute interstitial pattern of injury and diffuse interstitial fibrosis
Large atypical lymphoid infiltrate in the interstitium