IMPORTANT: We currently have a number of bugs related to image cropping and are actively trying to resolve them. In the meantime, we have disabled cropping. Apologies for any inconvenience. Stay informed: radiopaedia.org/chat

Xanthogranulomatous pyelonephritis

Case contributed by Frank Gaillard
Diagnosis certain

Presentation

Upper abdominal discomfort, vague constitutional symptoms and reduced renal function.

Patient Data

Age: Elderly
Gender: Female

Abdominal x-ray

x-ray

X-ray demonstrates a large right sided branched calculus which appears fragmented. 

CT demonstrates enlargement of the right kidney with multiple large renal calculi and rounded low-density regions associated with the calculus. The left kidney is markedly atrophic.

Annotated image

Single image from the CT with the right kidney outlined. Note how the dilated low-density calyces form an appearance which has been likened to that of the pads of a bear paw. 

MRI abdomen

mri

MRI demonstrates an enlarged right kidney with heterogeneous signal, hydronephrosis and a staghorn calculus. 

Case Discussion

Features are consistent with xanthogranulomatous pyelonephritis and pre-existing staghorn calculus.

Case courtesy of Dr Laura Jimenez Juan (CT) and Dr Natalie Yang (MRI)

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.