title: Xanthogranulomatous pyelonephritis presenting as a psoas abscess.
mesh_terms: D000038:Abscess / Q000209:etiology*; D000368:Aged; D005260:Female; D006099:Granuloma / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D009135:Muscular Diseases / Q000209:etiology; D011704:Pyelonephritis / Q000175:diagnosis* / Q000473:pathology; D014973:Xanthomatosis / Q000175:diagnosis* / Q000473:pathology