N-cadherin is differentially expressed in histological subtypes of papillary renal cell carcinoma

Background: Papillary renal cell carcinoma (RCC) represents a rare tumor, which is divided, based on histological criteria, into two subtypes. In contrast to type I papillary RCC type II papillary RCC shows a worse prognosis. So far, reliable immunohistochemical markers for the distinction of these subtypes are not available. Methods: In the present study the expression of N(neural)-, E(epithelial)-, P(placental)-, und KSP(kidney specific)cadherin was examined in 22 papillary RCC of histological type I and 18 papillary RCC of histological type II (n = 40). Results: All papillary RCC type II displayed a membranous expression for N-cadherin, whereas type I did not show any membranous positivity for N-cadherin. E-cadherin exhibited a stronger, but not significant, membranous as well as cytoplasmic expression in type II than in type I papillary RCC. A diagnostic relevant expression of P- and KSP-cadherin could not be demonstrated in both tumor entities. Conclusion: Thus N-cadherin represents the first immunhistochemical marker for a clear cut differentiation between papillary RCC type I and type II and could be a target for therapy and diagnostic in the future.