[Xanthogranulomatous pyelonephritis with septic lung metastases and infiltration of the colon. Difficult preoperative differential pulmonary hypernephroma metastasis diagnosis].

Xanthogranulomatous pyelonephritis (XGP) is a rare and aggressive form of chronic pyelonephritis for which partial or complete nephrectomy is mandatory [1.2]. The diagnosis and, in particular, the differentiation from hypernephroma is mostly established by the histopathological examination only. We have reviewed the literature and present an unusual case of XGP with septic spreading into the lungs mimicking pulmonary metastasis and with an inflammatory infiltration of the descending colon.