EGFR and cholangiocarcinoma: In spite of a relatively high prevalence of Egfr overexpression detected by immunohistochemistry (35.4% of cases with 2+ or 3+), only two cases had EGFR mutations and three had gene amplification, confirming the low prevalence reported in the literature in cholangiocarcinomas unassociated with chronic liver disease [14, 38, 41-44].