TTF1 and intrahepatic cholangiocarcinoma: In fact we carried out an extensive panel made up of epithelial markers (i.e. Keratins 7 and 20, AE1/AE3, CAM 5.2, ESA, Thyroid trascriptor factor-1 [TTF-1], E-cadherin, and others detailed in Table 3), mesenchymal markers (Vimentin, Desmin, neurofilaments) CD markers (CD10, CD15, CD30, CD45) or other markers (S100, mCEA, NSE, Calcitonin, HMB45).The ICC panels were carried out in both unknown primary tumors and in cases with a clinical neoplastic history but controversial cytological samples.