[Unusual clinical forms of presentation and infrequent pathologic associations of xanthogranulomatous pyelonephritis].

OBJECTIVE

To describe the unusual clinical forms and rare associations of xanthogranulomatous pyelonephritis seen in a variable proportion of cases.

METHODS

Analysis of our series of 83 cases and 2573 cases reported in the literature showed 8 different and less frequent clinical forms and up to 7 rare associations, which are discussed in this study.

RESULTS

There are different clinical forms under "renal infection", ranging widely from asymptomatic to severe septic forms that affect patients of all ages--from the newborn to the elderly-, preferentially in association with conditions of immunosuppression, and other more uncommon or rare forms in which xanthogranulomatous pyelonephritis is often incidentally discovered.

CONCLUSIONS

These forms are not extremely rare since more than 2500 cases have been reported in the literature. Knowledge about the different forms permits stratification of this condition into different clinical forms of presentation and provides further insight into the associated conditions, some of which are rare. Overall, such forms or associations have been reported to account for 20 to 40% of all cases, according to the studies reported elsewhere. This overall incidence is rather significant and should be taken into account.