Home   Chapter Home   Jobs   Conferences   Fellowships   Books


Kidney tumor - adult malignancies

Other neoplasms adult or adult/child

Metanephric / mesonephric adenosarcoma

Reviewers: Sean Williamson, M.D. (see Reviewers page)
Revised: 4 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.


● Very rare tumors with sarcomatous stroma and benign epithelium

Case reports

● Initial case described had rhabdomyoblastic differentiation (Am J Surg Pathol 1985;9:610)
● 21 year old woman with metanephric adenoma mixed with a malignant spindle cell component (Am J Surg Pathol 2001;25:1451)
● 56 year old woman (Pathol Int 2011;61:313)

Micro description

● Separate but contiguous or intimately mingled epithelial and stromal components
Epithelium: small cuboidal cells with scant cytoplasm, forming papillary projections, tubules, acini, solid-appearing areas, psammoma bodies, glomeruloid papillae (absence of necrosis/mitotic figures)
Stroma: spindle cell proliferation with high mitotic rate and necrosis

Positive stains

● Cytokeratin (AE1/AE3), vimentin

Negative stains


Differential diagnosis

Metanephric adenofibroma: stroma composed of benign fibroblast-like cells without significant atypia, increased mitotic rate or necrosis
Mesoblastic nephroma: smooth muscle differentiation in stromal component
Papillary renal cell carcinoma (with sarcomatoid component): cytokeratin 7 and EMA frequently positive, transition areas frequently present, chromosome 7 and 17 abnormalities

End of Kidney tumor - adult malignancies > Adult renal cell carcinoma > Metanephric / mesonephric adenosarcoma

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at [email protected] with any questions (click here for other contact information).