Xanthogranulomatous Pyelonephritis and Its Differential Diagnoses: An In-Depth Case Review

Xanthogranulomatous pyelonephritis is a rare chronic infectious process of the kidney, which has been described in three different forms: diffuse, segmental, and focal. It is also known as the great simulator since its clinical, radiological, and histopathological manifestations tend to be confused with other entities. We describe a case of a 55-year-old male patient with two months of clinical manifestations characterized by a 7x7-cm palpable mass in his right lumbar region, which was hot and painful upon touch and increasing in size. This article aims to present a case of xanthogranulomatous pyelonephritis and compare it with its primary differential diagnoses. It is evident that despite the condition being considered a simulating pathology, some key differences can be found to identify and distinguish it.