Two cases of gastric carcinoids: Diagnostic and therapeutic aspects

Abstract

AbstractTwo cases of gastric carcinoid tumors with the foregut carcinoid syndrome are presented. Due to elevated urinary levels of 5‐hydroxyindoleacetic acid (5‐HIAA), primary tumors of midgut origin were suspected. Provocation with pentagastrin (PG) elicited atypical flushing and severe bronchoconstriction, most probably caused by the release of histamine. Excessive excretion of the main histamine metabolite, tele‐methylimidazole acetic acid (MeImAA), in urine of both patients was demonstrated. Both patients had good symptomatic relief with prednisolone and blockade of histamine receptors. One of the patients had excessive secretion of serotonin (5‐HT) as well as of histamine. Peripheral blockade of 5‐HT2receptors was therefore added to the medical treatment. This patient had a subjective and biochemical response to cytotoxic treatment with streptozotocin and later responded well to a somatostatin analogue.On clinical suspicion of a foregut carcinoid tumor, or in patients with carcinoid tumors without anatomical localization, PG provocation should not be used until the excretion of MeImAA has been determined.