Carcinoma, Signet Ring CellStomach NeoplasmsDissectionAdenocarcinoma, MucinousGastroscopyAppendiceal NeoplasmsGastric MucosaUmbilicusCarcinomaMicrosatellite InstabilityGastrectomyRare DiseasesImmunohistochemistryMucinsAdenocarcinomaProto-Oncogene Proteins B-rafPeritoneal NeoplasmsCadherinsNeoplasm StagingColorectal NeoplasmsPyloric AntrumEndoscopy, GastrointestinalCarcinoma, Squamous CellLoss of Heterozygosityras ProteinsHistocytochemistryCarcinoma, HepatocellularNeoplasm InvasivenessPrognosisAlcian BlueMicrosatellite Repeats