Bear's Paw Sign: A Classic Presentation of Xanthogranulomatous Pyelonephritis.


Journal Article

A 41-year-old woman with recurrent urinary tract infections presented with right flank pain, fever, and anorexia. Physical examination revealed right-sided flank pain and a right-sided unilateral renal mass. Computed tomography of the abdomen and pelvis revealed xanthogranulomatous pyelonephritis with perinephric extension. The bear's paw sign was visualized. The classic radiology triad (unilateral large kidney, renal pelvis stone, and a nonfunctioning or poorly functioning kidney) was also found on computed tomographic imaging. She completed a course of antimicrobial therapy and underwent a nephrectomy. Her post-operative course was uneventful and she was discharged from the hospital on postoperative day 4.

Full Text

Duke Authors

Cited Authors

  • Tan, WP; Papagiannopoulos, D; Elterman, L

Published Date

  • August 2015

Published In

Volume / Issue

  • 86 / 2

Start / End Page

  • e5 - e6

PubMed ID

  • 26168999

Pubmed Central ID

  • 26168999

Electronic International Standard Serial Number (EISSN)

  • 1527-9995

International Standard Serial Number (ISSN)

  • 0090-4295

Digital Object Identifier (DOI)

  • 10.1016/j.urology.2015.04.033


  • eng