Small GISTs, including micro-GISTs and mini-GISTs, have KIT or PDGFRA mutations similar to those of clinical GISTs [16,35], and familial GISTs with germline mutations in KIT or PDGFRA accompanied by diffuse hyperplasia of ICC cells and multiple micro-GISTs and mini-GISTs with benign features [18,19,36]. This evidence concerns the gene PDGFRA and intrahepatic cholangiocarcinoma.