Figure 2: Pathohistological findings of the gastric tumor biopsy. The tumor was composed of nests of hyperchromatic and pleomorphic neoplastic cells in solid and glandular patterns. (a) Component of adenocarcinoma. (b) Component of squamous cell carcinoma. (c) The component of adenocarcinoma showed HNF4α expression by immunohistochemistry. (d) Increased PD-L1 expression by immunohistochemistry. HNF4 α: Hepatocyte nuclear factor 4 alpha, PD-L1: Programmed death-ligand 1