When we compared the relationship between the morphological types according to the WHO 2019 classification and the presence of HER2 amplification in our series of tubular adenocarcinomas, the frequency of detection of amplification was found to be significantly higher than poorly cohesive carcinoma, mucinous adenocarcinoma, and CWLS (P < .000). The gene discussed is ERBB2; the disease is mucinous adenocarcinoma.