[N-cadherin as a novel diagnostic marker : Differentiation of primary liver tumours from metastases of an extrahepatic primary tumour].

The differential diagnosis of intrahepatic cholangiocarcinomas (iCCA), hepatocellular carcinomas (HCC) and liver metastases of extrahepatic primary tumours is crucial but may be challenging. N‑cadherin, a transmembrane glycoprotein of adherens junctions, is typical for neural and mesenchymal cells, whereas most epithelia and carcinomas derived therefrom are negative for N‑cadherin. However, hepatocytes and cholangiocytes, along with HCC and iCCA, are exceptions as they exhibit expression of N‑cadherin, making this a valuable immunohistochemical marker. We previously showed in a study on 3359 tumours that N‑cadherin positivity reliably differentiates primary liver carcinomas from liver metastases of extrahepatic carcinomas. N‑cadherin therefore complements the immunohistochemical panel in the differential diagnosis of carcinoma of unknown primary (CUP).