In total, four out of eight cases showed poorly differentiated ampullary adenocarcinomas with prominent signet ring cells floating in the pools of mucous, two of these cases were positive for CK7, CK19 and MUC1, while only one was positive for CK7, CK19, MUC1 and CD10. This evidence concerns the gene MUC1 and ampulla of vater adenocarcinoma.