MUC5AC and intrahepatic cholangiocarcinoma: In 1985, Goodman et al., based on 24 other cases, first used the term CHCC-ICC and re-categorized it into three histologic variants: type I or “collision tumors”—incidental diagnosis of HCC and ICC separately in the same liver (Allen type B); type II or “transitional tumors”—one single tumor with a progressive transition between HCC and ICC areas (Allen type A + C); and type III or “fibrolamellar tumors”—intermingled areas with histologic similarities to the fibrolamellar variant of HCC but with mucin-producing foci or pseudoglands (Brunt et al. 2015; Yin et al. 2012; Goodman et al. 1985).