The etiopathogenesis of xanthogranulomatous pyelonephritis. With referenceto two cases

Xanthogranulomatous pyelonephritis (XGP) is an uncommon inflammatory diseas e of the kidney whose diagnosis is histological. Nephrectomy and antimicrob ial therapy are usually required. Two cases that may provide lessons for th e as yet poorly understood etiopathogenesis of XGP are reported. These pati ents were a man and a woman, both aged 56 years, with a negative history fo r diabetes mellitus and urinary tract disease. The diagnosis was made upon examination of a left nephrectomy specimen. The pre- and intraoperative dia gnosis in the woman was renal cancer. The man had undergone resection of an aneurysm of the abdominal aorta seven months earlier; during the procedure , the blood vessels to the left kidney had been manipulated. The left kidne y was atrophic and surrounded by a collection of aseptic purulent fluid; xa nthogranulomatous modifications were seen upon histology. In both patients, gammaglobulin levels were increased during the episode of XGP and returned to normal following nephrectomy. Conclusion: these two cases support the p ossibility that XGP may be a systemic disease (Papo Th., Piette J.C., Kahn) , In the second patient, the onset after manipulation of the blood vessels to the kidney is additional evidence for the vascular pathogenetic theory.