Lung and lymph node metastases from hepatocellular carcinoma: Comparison of pathological aspects

Background & Aims Extrahepatic metastasis from hepatocellular carcinoma (HCC) is a catastrophic event, yet organ‐specific pathological characteristics of metastatic HCC remain unclear. We aimed to characterize the pathological aspects of HCC metastases to various organs. Methods We collected intrahepatic HCC (cohort 1, n = 322) and extrahepatic metastatic HCC (cohort 2, n = 130) samples. Clinicopathological evaluation and immunostaining for K19, CD34, αSMA, fibroblast‐associated protein (FAP), CAIX, VEGF, PD‐L1, CD3, CD8, Foxp3, CD163 and epithelial–mesenchymal transition (EMT)‐related markers were performed. Results Independent factors for extrahepatic metastasis included BCLC stage B–C, microvascular invasion (MVI), vessels encapsulating tumour clusters (VETC)‐HCC, K19 and FAP expression, and CD163+ macrophage infiltration (cohort 1, P