Brenner TumorAdenocarcinoma, MucinousNeoplasms, Glandular and EpithelialAdenocarcinomaAppendiceal NeoplasmsCarcinoma, Signet Ring CellPseudomyxoma PeritoneiRectal FistulaCystadenomaLinitis PlasticaCecal NeoplasmsCystadenoma, MucinousThymus NeoplasmsOvarian NeoplasmsImmunohistochemistryMesocolonUrachal CystCalymmatobacteriumCystadenocarcinomaCystadenocarcinoma, MucinousPerineumThymomaTumor Markers, BiologicalMucin-2CarcinomaNeoplasms, Multiple PrimaryColorectal NeoplasmsMucinsAdenomaStomach NeoplasmsNeoplasm StagingKeratinsColonic NeoplasmsRectal NeoplasmsPancreatic NeoplasmsPrognosisMicrosatellite Instability