Kidney tumor - cysts, children, adult benign
Benign (usually) adult tumors
Fibroepithelioid polyp of renal pelvis

Author: Mandolin Ziadie, M.D. (see Authors page)

Revised: 17 January 2017, last major update January 2012

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Fibroepithelioid polyp [title] AND renal pelvis

Cite this page: Fibroepithelioid polyp of renal pelvis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/kidneytumorfibroepithelialpolyp.html. Accessed February 23rd, 2017.
Definition / General
  • Mesodermal tumor that is more commonly diagnosed in the ureter
Epidemiology
  • Rare (< 50 cases reported)
Clinical Features
  • Presents in young adults (usually women) with gross and painless hematuria
  • Xray: polypoid filling defect on intravenous pyelogram
Radiology Images

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Polypoid filling defect on intravenous pyelogram

Case Reports
Treatment
  • Benign; local resection if causes obstruction
Gross Description
  • Polypoid exophytic mass with smooth glistening external surface and gray / white / pink cut surface
Gross Images

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Large polyp almost completely fills renal pelvis

Micro Description
  • Thick fibrous stalk and connective tissue core covered by urothelium
  • Connective tissue core contains collagen, smooth muscle and blood vessels with edema and inflammatory cells
Micro Images

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Urothelium covers
fibrovascular tissue
with loose stroma and
small blood vessels

Negative Stains
Differential Diagnosis
  • Hemangioma: vascular lesion, no fibrous stalks and no urothelial cells
  • Leiomyoma: smooth muscle cells, no fibrovascular stalks and no urothelium
  • Schwannoma: neural features, no smooth muscle cells, no fibrovascular stalks and no urothelium; S100+