Abstract: SA-PO0972
Hidden Culprit: Nongranulomatous Tubulointerstitial Nephritis as a Renal Manifestation of Systemic Sarcoidosis
Session Information
- Pathology: Updates and Insights
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Aamir, Nawal, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States
- Aulakh, Gagan, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States
- Singh, Arshdeep, Late Baliram Kashyap Memorial Government Medical College, Jagdalpur, CT, India
- Chutani, Arun, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States
Introduction
Sarcoidosis is a multisystem disorder characterized by non-caseating granulomas that primarily affects the lungs and lymph nodes. Renal involvement sarcoidosis is rare, occurring in approximately 0.7% of cases. Notably, while granulomatous interstitial nephritis (GIN) is traditionally associated with renal sarcoidosis, non-granulomatous tubulointerstitial nephritis (TIN) is actually more common, representing 44% of renal sarcoidosis cases compared to 30% for GIN. Non-granulomatous TIN represents the common histological pattern in renal sarcoidosis. This presentation poses diagnostic challenges, as the absence of granulomas may lead clinicians to overlook sarcoidosis as the underlying etiology. The diagnosis relies on a constellation of clinical, laboratory, and histological features, including evidence of sarcoidosis in other organ systems.
Case Description
A 62-year-old female with type 2 diabetes and hypertension presented with hypercalcemia (calcium 12.5 mg/dL). Imaging revealed multiple hypodensities in liver, spleen, and lungs. Liver biopsy demonstrated non-caseating granulomas with giant cells, supporting the diagnosis of systemic sarcoidosis. The patient subsequently developed AKI (creatinine 2.08 mg/dL from baseline 0.8 mg/dL). Kidney biopsy revealed TIN without granulomas. Renal sarcoidosis was diagnosed based on systemic sarcoidosis affecting multiple organs. Treatment with prednisone (1 mg/kg daily) resulted in improved renal function, though persistent microalbuminuria suggested ongoing tubular dysfunction. The patient was later transitioned to hydroxychloroquine 400 mg daily with successful prednisone taper. Creatinine stabilized between 1.0-1.3 mg/dL. Chest CT demonstrated findings consistent with stage II pulmonary sarcoidosis.
Discussion
This case illustrates that non-granulomatous TIN can be a manifestation of sarcoidosis, even without renal granulomas. The diagnosis relies on identifying sarcoidosis in other organ systems and excluding alternative causes of interstitial nephritis. According to established criteria, TIN due to sarcoidosis can be diagnosed with evidence of sarcoidosis in at least two other organs plus clinical features of TIN. Corticosteroids remain the cornerstone of therapy for renal sarcoidosis, with steroid-sparing agents like hydroxychloroquine offering alternatives for long-term management.