Kidney nontumor / medical renal
Infection
Xanthogranulomatous pyelonephritis
Author: Nikhil Sangle, M.D.
Last author update: 4 August 2014
Last staff update: 2 June 2023 (update in progress)
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Xanthogranulomatous pyelonephritis
Table of Contents
Definition / general | Clinical features | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Sangle N. Xanthogranulomatous pyelonephritis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/kidneyxantho.html. Accessed June 2nd, 2023.
Definition / general
- Rare, severe, atypical form of chronic pyelonephritis due to infection (E. coli, Proteus) or stones, but resembling renal cell carcinoma; correct preoperative diagnosis is unusual (Arch Pathol Lab Med 2011;135:671, Arch Dis Child 1999;81:483)
- Characterized by foamy histiocytes replacing renal parenchyma
- High index of suspicion necessary for preoperative diagnosis, intraoperative urine culture may be helpful (Int Urol Nephrol 2011;43:15, Tunis Med 2010;88:427)
Clinical features
- Destructive inflammatory process that may complicate chronic pyelonephritis
- Usually unilateral, ages 40+, 67% women
- Associated with pelvicalyceal obstruction and ulceration
- Rarely coexists with squamous cell carcinoma, renal cell carcinoma (J Cancer Res Ther 2010;6:339, ScientificWorldJournal 2009;9:5)
Case reports
- 51 year old woman with Liesegang rings (Patholog Res Int 2010;2010:602523)
- 68 year old man with cirrhosis and 2.9 cm renal mass (Case #323)
- 68 year old woman with fever of unknown origin and renal mass (Heart Lung 2012;41:606)
Gross description
- Multiple yellow nodules around calyces, may form a mass and be infiltrative
Gross images
Images hosted on other servers:
Various images
Microscopic (histologic) description
- Replacement of renal parenchyma with CD68+ foamy histiocytes, occasional multinucleated giant cells and inflammatory cells
Microscopic (histologic) images
Differential diagnosis
- Malakoplakia: Michaelis-Gutmann bodies
- Renal clear cell carcinoma: Cells with clear cytoplasm may resemble histiocytes, but are keratin+, CD68-; arranged in compact, tubulocystic, alveolar or rarely papillary patterns; often glassy hyaline globules; usually nuclear grade 2 or higher; chicken wire / delicate vasculature is common (sinusoids near each packet of cells)
- Renal replacement lipomatosis: atrophic renal parenchyma is replaced by fatty tissue, not xanthoma cells (Rev Assoc Med Bras 2011;57:262)
