ERBB2 and hepatoid adenocarcinoma: Interestingly, in a previous analysis concerning unusual histotype of GC, we have already documented a progressive increase of HER2 amplification moving from the poorly cohesive histotype to the mitochondrion-rich adenocarcinoma, tubular adenocarcinoma, and hepatoid carcinoma, which showed the highest frequency of HER2 positivity and the worse prognosis [12, 21].