All of the following statements about Xanthogranulomatous are true except
**Core Concept**
Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis characterized by the destruction of renal tissue and the presence of histiocytic granulomas, xanthoma cells, and foamy macrophages. It is often associated with an obstructing renal stone or chronic urinary tract infection.
**Why the Correct Answer is Right**
XGP is a type of destructive renal disease that typically affects the upper pole of the kidney. The condition is characterized by the presence of xanthoma cells, which are lipid-laden macrophages, and histiocytic granulomas. The disease is often associated with an obstructing renal stone or chronic urinary tract infection, which leads to chronic inflammation and tissue destruction. The inflammation and tissue destruction in XGP can lead to the formation of a mass that may mimic a renal tumor.
**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect as XGP is not typically associated with a normal kidney structure. XGP is often associated with chronic urinary tract infections and obstructing renal stones, which can lead to renal tissue destruction.
**Option B:** This statement is incorrect as XGP is not typically caused by a bacterial infection. While bacterial infections can contribute to the development of XGP, the condition is often associated with chronic urinary tract infections and obstructing renal stones.
**Option C:** This statement is incorrect as XGP is not typically a benign condition. XGP can lead to significant renal tissue destruction and may require surgical intervention.
**Clinical Pearl / High-Yield Fact**
XGP is often associated with an obstructing renal stone or chronic urinary tract infection, and the condition can mimic a renal tumor on imaging studies. Therefore, it is essential to consider XGP in the differential diagnosis of a renal mass or mass-like lesion.
**Correct Answer:** D.