黃色肉芽腫腎孟腎炎是一種罕見，嚴重，慢性腎臟感染，典型之臨床表現為腎臟擴大及腎功能喪失，且通常由於尿路結石所引起阻塞性尿路病變而導致。延遲診斷及治療可造成腎臟功能喪失甚至危及生命。在此我們報導一個病人於左側腰部有一凸起腫塊，最後診斷為黃色肉芽腫腎孟腎炎，此病患經哥|流及腎臟切除術後恢復良好。相關的診斷及治療將討論於後。

Xanthogranulomatous pyelonephritis (XGPN) is a rare, severe, chronic renal infection typically resulting in a non-functioning enlarged kidney and is associated with obstructive uropathy secondary to nephrolithiasis. Delay in diagnosis and treatment may result in loss of a kidney and death. Here we report a patient who had a protruding mass over the left sided flank as the initial presentation of XGPN. She was managed successfully by percutaneous drainage followed by nephrectomy. The relevant issues regarding diagnosis and treatment of this disease are discussed.