Which of the following statements about Xanthogranulomatous pyelonephritis is not true ?

Ans. is 'b' i.e., Associated with tuberculosisXanthogranulomatous pyelonephritis o Xanthogranulomatous pyelonephritis is a chronic infective condition of the kidney associated with chronic bacterial infection.o The most common organism implicated in causation is proteus followed by E coli (not tuberculosis). o Most of the cases occur in old ages (5th-6" decade), but may occur at any age.o Females are more commonly affected.o Usually involves one kidney (unilateral), but may be bilateral.o Affected kidney, almost always has:(i) Obstruction (large staghorn calculus)(ii) HydronephrosisPathological findings1. Gross featureso Enlarged kidney o Dilated pelvisStones of staghorn varietyo Calyces are typically filled with pusCoex is studded with yellowish nodules that line the calyces (Granulomatous areas).2. Microscopic featureso Yellow nodules are due to large foam cells (lipid laden histiocytes). Also known as Xanthoma cells.o These foam cells contain lipid and PAS positive granuleso Along with foam cells, lymphocytes, plasma cells and multinucleated giant cells are also present.o Lymphoid follicles may be seen.o Fibrosis may be seen which may contain foreign body giant cells.o Foci of calcification may be seen.