11^th Global Gastroenterologists Meeting

A 66-year-old Japanese male was shown to have severe ulcers with hypergastrinemia in the stomach through proximal horizontal part of the duodenum. He suffered from gastric ulcer at 63 and hyperparathyroidism at his 5th decade. Though he had no definitely enlarged pituitary detectable by computed tomography, he had slight defects in the visual field and hyperprolactinemia. A diagnosis of multiple endocrine neoplasia type 1 (MEN1) was entertained. Follow up EGD revealed five small sessile submucosal tumors (SMTs) with a central depression or erosion in the duodenal bulb through descending part of the duodenum, which had been obscured beneath ulcers. Demonstrated in the regenerative mucosa by biopsy were clusters of small tumor cells, which, though considered the tips of neuroendocrine (NE) tumor (NET) in the deeper layer, were not large enough to be proven so by immuno staining with the markers in the serial sections, and diffuse hyperplasia of synaptophysin-, chromogranin A- and gastrin-positive NE cells in brunner glands (BGs), the preneoplastic lesion characteristic of MEN1-associated duodenal gastrinoma, supporting the diagnosis, which was firmly guaranteed by positively elevated glucagon-provoked plasma gastrin. Subtotal stomach-preserving pancreaticoduodenectomy established the final diagnosis of duodenal gastrinoma graded G1 associated with MEN1, which were shown to be tightly contained in the densely conglomerated hyperplastic BGs. Difficulty in endoscopically detecting the NET lies in the fact that, in addition to its smallness and deep localization, it might be buried under peptic ulcer at a certain stage and that an attempt to biopsy it is hampered by the densely conglomerated hyperplastic BGs in some cases.