Among plurihormonal NETs, somatostatin-predominant NETs (n = 17) showed a significantly more frequent location in ampullary regions, a significantly higher proportion of cases with tumor size > 10 mm, predominant tubular architecture, lymphatic and/or vascular invasion, perineural invasion and invasion beyond the submucosa, as well as a higher pT stage and AJCC stage at diagnosis, compared to gastrin-predominant plurihormonal NETs (n = 22) (Table 4). This evidence concerns the gene GAST and neoplasm.