Case report: Xanthogranulomatous pyelonephritis successfully treated with antibiotics.

Xanthogranulomatous inflammation (XGI) is an uncommon benign inflammatory disease process characterized by aggregation of lipid laden foamy macrophages, among other inflammatory cells. XGI affecting the kidney and renal pelvis is otherwise known as xanthogranulomatous pyelonephritis (XGP), which has been reported to be present in approximately 5% of all reported xanthogranulomatous cases. The clinical relevance of this disease is that it often mimics malignancy, and preoperative imaging is unable to differentiate between the two. Our case report demonstrated a renal lesion that mimicked malignancy and ultimately required histopathological examination for the diagnosis of XGP. Current consensus remains that surgery is the mainstay form of treatment. However, this case report showed that use of antibiotics alone can be successful as the patient showed significant improvement and resolution on interval imaging.