Carcinoid TumorProctoscopyProctoscopesMalignant Carcinoid SyndromeRectal NeoplasmsIleal NeoplasmsCarcinoid Heart DiseaseBronchial NeoplasmsAppendiceal NeoplasmsGastrointestinal NeoplasmsNeuroendocrine TumorsChromograninsIntestinal NeoplasmsOctreotideChromogranin AHydroxyindoleacetic AcidACTH Syndrome, EctopicEnterochromaffin-like CellsDuodenal NeoplasmsThymus NeoplasmsEnterochromaffin CellsCarcinoma, NeuroendocrineEndocrine Gland NeoplasmsReceptors, SomatostatinGastrinsTumor Markers, BiologicalLung NeoplasmsStomach NeoplasmsSomatostatinIndium RadioisotopesParaneoplastic Endocrine SyndromesPolypsNeoplasms, Multiple PrimaryZollinger-Ellison SyndromeMultiple Endocrine Neoplasia Type 1Liver NeoplasmsDigestive System NeoplasmsCommon Bile Duct NeoplasmsPancreatic NeoplasmsImmunohistochemistryCell Line, TumorCarcinoma, Small CellPentetic Acid3-IodobenzylguanidineAmpulla of VaterMuridaeNeoplasm MetastasisTomography, X-Ray ComputedAnemia, PerniciousSynaptophysinAppendixJejunal NeoplasmsAdenoma, Islet CellSerotoninCushing SyndromeAdenocarcinomaTumor BurdenDuodenoscopy