Mixed focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) within a single tumor mass is rarely reported, and most of these cases are examples of tumors with features intermediate between FNH and HCA. Although a few reported cases are probably examples of true mixed tumors, none was evaluated immunohistochemically or confirmed by molecular analysis. We report a mixed FNH and HCA arising in a woman with several HNF1A-inactivated adenomas. Our case is the first case of mixed FNH and HNF1A-inactivated HCA documented by immunohistochemistry.