Material and Method: Medical records of adults who underwent a kidney biopsy procedure in our institution between January 2000 and June 2019 were reviewed. Pathology reports were searched for biopsies where a granuloma was identified.

Results: Nineteen of 1121 (1.7%) kidney biopsies included granuloma, 17 in native kidneys, and 2 in transplants. The majority of indications for native kidney biopsy was a rise in serum creatinine. Etiologies of granuloma included the following: pauci-immune vasculitis (n=11, 64.7%), tuberculosis (n=2, 11.8%), drug-induced (n=2, 11.8%), tubulointerstitial nephritis/uveitis (TINU) syndrome (n=1, 5.9%), and systemic-lupus erythematosus (n=1, 5.9%). Despite treatment, 6 of 11 (54.5%) patients with vasculitis developed end-stage kidney disease (ESKD) during the median follow-up of 16 months. Both of the patients with tuberculosis, and the patient with TINU syndrome developed ESKD months after the kidney biopsy, despite appropriate therapies. The only case with drug-induced granuloma and both cases with allograft kidney granuloma responded well to glucocorticoids, achieving a complete renal recovery.