Pan-cytokeratin immunoexpression in Wilms' tumors: a simple approach for understanding tumor epithelial differentiation.

Wilms' tumor is one of the most common solid tumors in children and is an interesting model for understanding the pathogenesis of embryonal tumors. Cytokeratins are intracellular fibrous proteins present in tissue of epithelial origin. The immunoexpression of the pan-cytokeratin AE1AE3 was studied in paraffin-embedded tissue sections from 24 Wilms' tumors (12 with nephrogenic rests) and also tissue samples from 15 corresponding normal kidneys, to evaluate epithelial differentiation in the genesis of Wilms' tumor. We observed that the intensity of the expression of AE1AE3 in the epithelial component of Wilms' tumors directly correlated with the degree of maturity of the epithelial structures correspondent to the collecting ducts.