[Systemic amyloidosis secondary to xanthogranulomatous pyelonephritis]

Secondary amyloidosis is a relatively common pathology in which chronic infectious diseases are common causes, especially infected bronchiectasis, osteomyelitis or chronic ulcers. The association of xanthogranulomatous pyelonephritis and systemic amyloidosis is extremely rare. To our knowledge, despite innumerable cases of xanthogranulomatous pyelonephritis reported in the literature, this association has been reported in only 8 previous cases. Patients usually complain of fever, back or flank pain and urinary tract symptoms. A long lasting evolution of the process is frequent. We report a 70 year old patient who developed amyloidosis secondary to xanthogranulomatous pyelonephritis. As well as the rarity of this association, this case is exceptional in its clinical presentation, without any urinary tract symptoms that could suggest the diagnosis.