Background: CDX1 and CDX2 are transcription factors involved in the development and maintenance of the intestinal epithelial cell. Expression of CDX2 has been reported in normal and metaplastic intestinal epithelium, and in those adenocarcinomas with that cellular origin. We have analyzed the expression of this marker in reactive and tumoral lesions arising in urinary bladder, urethra and urachus.
Method: CDX2 was investigated through immunohistochemistry on paraffin-embedded tissue, using the labelled streptavidin-biotin method (LSAB2, Dako) with a monoclonal antibody (CDX2-88, BioGenex).
Results: Expression of CDX2 was observed in intestinal-type cistitis glandularis, intestinal metaplasia of urinary bladder, bladder adenocarcinoma, mucinous urothelial-type carcinoma of prostatic urethra and urachal mucinous carcinoma. CDX2 was not detected in normal urothelium and prostatic glandular epithelium, Von Brunn nests, typical-type cistitis glandularis, glandular adenosis and transitional carcinoma.
Conclusions: Lesions, both benign and malignant, with enteric-cell morphological features show positivity for CDX2. Expression of this marker is not organ-specific but is just related to a cellular phenotype. Reactivity for CDX2 in an adenocarcinoma can be consistent with an origin in urinary tract or urachus.