Presentation
Motorcycle accident with abdominal pain.
Patient Data
Massive and abnormal right kidney: central stone, calyces blown out with layering calcifications, dense material in upper/posterior calyx which does not definitely enhance pre/post contrast.
Small amount of retroperitoneal/peripancreatic fluid. Mild thickening/hyperenhancement of the right ureter with surrounding fluid.
Right hip subcutaneous hematoma.
Hepatic steatosis.
Case Discussion
Massive hydronephrosis of the right kidney discovered in the setting of trauma.
The dense material in the upper pole is initially concerning for urothelial tumor, but does not enhance and may be blood products related to the trauma.
This is an extremely abnormal kidney. In terms of the distinction between severe hydronephrosis and xanthogranulomatous pyelonephritis (XGP), a few comments can be made: First, this is a chronically obstructed kidney due to a central staghorn stone with areas of thickening/fibrosis. Several of the calyces appear isolated due to fibrosis. There is some component of chronic inflection and inflammation here.
The distinction of this being xanthogranulomatous or not (filled with lipid laden macrophages) probably doesn't matter. XGP often will rupture/decompress into the retroperotoneum, and does not usually reach this size. This is a surgical case either way.