Supplementary Material for: Hepatic progenitor cells in the form of ductular structures within a GIST liver metastasis: supporting a putative role in the hepatic metastatic niche

Recent studies have highlighted the presence of hepatic progenitor cells (HPCs) in metastatic liver carcinomas. We provide further evidence of this phenomenon, presenting a case of a gastrointestinal stromal tumour (GIST) liver metastasis with evidence of intra- and peritumoral HPC. A 64-year-old man presented with a gastric mass diagnosed as a high-risk KIT-mutated GIST. The patient was treated with Imatinib, recurring five years later with a liver mass. Liver biopsy disclosed a GIST metastasis, hallmarked by a proliferation of ductular structures without cytological atypia intermingled with the tumour cells, with a CK7/CK19/CD56-positive immunophenotype and rare CD44 positivity. The patient underwent liver resection, and the same ductular structures were present in the tumour interior and at its periphery. We document for the time the presence of HPC in the form of ductular structures in a GIST liver metastasis, further supporting their role in the liver metastatic niche.

近期研究已证实，转移性肝癌中存在肝祖细胞（hepatic progenitor cells, HPCs）。本研究为该现象提供了进一步证据，报道1例伴瘤内及瘤周肝祖细胞表现的胃肠道间质瘤（gastrointestinal stromal tumour, GIST）肝转移病例。患者为64岁男性，因胃部肿块就诊，经诊断为高危型KIT突变型胃肠道间质瘤。患者接受伊马替尼治疗，5年后复发并出现肝脏肿块。肝活检证实为胃肠道间质瘤转移，其特征为肿瘤细胞间混杂有导管样结构增生，无细胞学异型性，免疫表型呈CK7/CK19/CD56阳性，CD44阳性少见。患者接受肝切除术，肿瘤内部及外周均可见上述导管样结构。本研究首次报道了胃肠道间质瘤肝转移灶中以导管样结构形式存在的肝祖细胞，进一步证实了其在肝脏转移微环境中的作用。