Carcinoma, Signet Ring CellAdenocarcinoma, MucinousStomach NeoplasmsAppendiceal NeoplasmsUmbilicusCarcinomaMicrosatellite InstabilityGastrectomyRare DiseasesImmunohistochemistryMucinsAdenocarcinomaProto-Oncogene Proteins B-rafPeritoneal NeoplasmsCadherinsPyloric AntrumEndoscopy, GastrointestinalNeoplasm StagingColorectal NeoplasmsCarcinoma, Squamous Cellras ProteinsLoss of HeterozygosityCarcinoma, HepatocellularHistocytochemistryNeoplasm InvasivenessPrognosisAlcian BlueMicrosatellite Repeats