LAUSR

Gastrinoma, which is also known as G-cell (gastrinproducing) neuroendocrine tumor (NET), is usually developed in stomach, pancreas, and duodenum and, the last two, can associate Zollinger–Ellison syndrome (ZES) [1, 2]. The incidence of gastrinoma-related ZES is about 1–1.5 cases/million/year [1]. Duodenal gastrinomas are extremely rare tumors, with an incidence of 0.04–0.19/100000 [2]. They occur, in 20% of the cases, in patients with multiple neuroendocrine syndromes (usually autosomal dominant MEN1) but can also be a sporadic tumor [1]. In this paper, we present a rare case of sporadic duodenal gastrinoma with muscular hypertrophy of the duodenal wall, mimicking a gastrointestinal stromal (GIST). As germline mutation of the MEN1 gene, located on chromosome 11q13, is characteristic for MEN1-related NETs [1, 3], MEN1 gene sequencing was also performed. The particularity of the paper is identification, for the first time in literature, in patients with multifocal gastrinomas, of the polymorphism D418D (rs2071212), in exon 9 of MEN1 gene, as a benign/likely benign polymporphism, in association with muscular hypertrophy of the duodenal wall. Only 26 cases of idiopathic muscular hypertrophy of the duodenum were previously published, only one of them in the last 35 years, without association with other tumors [4].