Xanthogranulomatous pyelonephritis in a renal allograft recipient.

Xanthogranulomatous pyelonephritis rarely occurs in renal allografts. This is the fifth reported case. Diagnosis was made by renal biopsy, which is usually performed to evaluate an elevated serum creatinine. Associated patient symptomology is nonspecific, and graft imaging with ultrasonography and computed tomography was not helpful as it would be with native kidney xanthogranulomatous pyelonephritis. Successful treatment with antibiotics may depend on the serum creatinine at presentation. Prognosis, therefore, is guarded, with a common outcome of irreversible renal dysfunction.