Kidney tumor
Childhood tumors
Metanephric stromal tumor

Topic Completed: 1 December 2011

Minor changes: 10 December 2020

Copyright: 2003-2019,, Inc.

PubMed Search: "Metanephric stromal tumor" kidney

Mandolin S. Ziadie, M.D.
Page views in 2020: 1,711
Page views in 2021 to date: 75
Cite this page: Ziadie MS. Metanephric stromal tumor. website. Accessed January 18th, 2021.
Definition / general
  • Benign spindle cell neoplasm of pediatric kidney composed of bland spindled cells that entrap native kidney
  • Similar to and often misdiagnosed as mesoblastic nephroma
  • May be related to Wilms tumor (Clin Lab Med 2005;25:379)
  • Excision is curative
Gross description
  • Fibrous lesion centered in renal medulla containing smooth walled cysts; mean 5.5 cm
Microscopic (histologic) description
  • Nodular low power appearance
  • Identical to stromal component of metanephric adenofibroma
  • Bland spindle cells with thin, tapered and hyperchromatic nuclei and indistinct cytoplasm (may have epithelioid areas) that entrap native kidney, usually undermine calyceal or pelvic urothelium and may entrap nerves
  • Nonencapsulated with a scalloped border with renal cortex
  • Hypo and hypercellular areas with onion skin cuffing around entrapped renal tubules
  • Stroma may show glial, cartilaginous or neuroblastic differentiation
  • Angiodysplasia of entrapped arterioles
  • May show juxtaglomerular cell hyperplasia in entrapped glomeruli
  • No vascular invasion, no mitotic figures
Positive stains
Negative stains
Differential diagnosis
Back to top
Image 01 Image 02