CTNNB1 and intrahepatic cholangiocarcinoma: Sarcomatous cHCC-ICC should be differentiated from the newly described pseudoendocrine sarcoma, in which cells are marked by nuclear β-catenin (reflecting mutations of the CTNNB1 gene), and show focal positivity for S100, desmin, and CD34, and negativity for CTKs (Papke et al. 2022).