Coexpression of cytokeratins 7 and 20 confirms urothelial carcinoma presenting as an intrarenal tumor

• Published in: Cancer Vol. 86; no. 11; pp. 2327 - 2330
• Main Authors: Han, Aaron C., Duszak, Richard
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01-12-1999; Wiley-Liss
• Subjects: Aged; Biological and medical sciences; Biomarkers, Tumor - analysis; Carcinoma, Renal Cell - diagnosis; Carcinoma, Transitional Cell - diagnosis; Carcinoma, Transitional Cell - pathology; cytokeratin subtypes; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Intermediate Filament Proteins - analysis; Keratin-20; Keratin-7; Keratins - analysis; Kidney; Kidney Neoplasms - diagnosis; Kidney Neoplasms - pathology; kidney tumors; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Tumors of the urinary system; Urinary tract. Prostate gland; urothelial carcinoma; Human; Kidney disease; Immunohistochemistry; Cytokeratin; Urinary system disease; Radiodiagnosis; Malignant tumor; Urinary tract disease; Transitional cell carcinoma; Intrarenal; Urinary tract; Differential diagnostic; Case study; Pathology; Medical imagery; Adult; Female; Computerized axial tomography
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/(SICI)1097-0142(19991201)86:11<2327::AID-CNCR21>3.0.CO;2-D

BACKGROUND
The differentiation of epithelial tumors arising in the kidney (urothelial vs. renal cell carcinoma) sometimes can be difficult by clinical and radiologic studies. Because urothelial and renal epithelium express unique cytokeratin (CK) 7 and 20 profiles, the authors studied the utility of these markers to confirm the diagnosis of urothelial carcinomas that present clinically as kidney masses.
METHODS
Using commercially available monoclonal antibodies, paraffin section immunohistochemistry was used to examine two recent cases of urothelial carcinomas presenting as renal tumors. Tissues were stained for CK7 and CK20 and the expression compared between the tumor and benign tissue.
RESULTS
Both cases showed solid renal masses that clinically and radiographically could have been of renal cell origin, but subsequently were confirmed histologically to be extensive renal involvement by urothelial carcinoma. The tumors coexpressed both CK7 and CK20, which is the expected profile for carcinomas of urothelial but not renal origin.
CONCLUSIONS
The results of the current study show that coexpression of CK7 and CK20 is a useful diagnostic aid in the differential diagnosis of epithelial kidney tumors of urothelial cell versus renal cell origin. Cancer 1999;86:2327–30. © 1999 American Cancer Society.
Coexpression of cytokeratins 7 and 20 is a useful diagnostic marker to differentiate intrarenal tumors of urothelial origin from those of renal cell origin.