Sporadic, Non‐Functional , Gastrin‐Producing Duodenal Neuroendocrine Tumors: A Retrospective Study of an Infrequent Disease

Abstract

Objective non-functioning gastrin-producing Neuroendocrine Neoplasms (NEN) of the duodenum are rare tumors of the gastrointestinal tract without a clinical syndrome due to gastrin-production. Their incidence has significantly increased in the last few years especially as an incidental finding during endoscopic studies. The aim of this study is to describe the characteristics of this emergent neoplasm, to provide more information on this rare pathology and its possible prognostic factors.

Methods we performed a retrospective observational study based on the duodenal-NENs samples with positive staining for gastrin, registered in the Pathology Department of University Hospital 12-de-Octubre (Madrid, Spain) between 2000 and 2017. We excluded all those clinically functional [(Zollinger-Ellison-Syndrome) and/or gastrinemia >1000pg/ml], with a previous diagnosis of multiple endocrine neoplasia(MEN-syndrome) or a synchronous neoplasia. Clinicopathological and therapeutic variables, follow-up time, recurrence and mortality data were collected.

Results 21 patients were included. Most of the tumors were diagnosed incidentally as a single small polypoid lesion, they were limited to mucosa/submucosa and had a low histological-grade. 4 patients (19%) presented metastatic involvement at diagnosis (lymphatic and/or hepatic). These 4 patients also had a high or intermediate mitotic grade and infiltration further than submucosa. Local resection was used in most cases as curative treatment. The median follow-up was 25 months. There were 2 relapses and 2 deaths attributed to the tumor with a 5-year disease-free-survival of 81%.

Conclusions The majority of these tumors were diagnosed at a local stage and had a good prognosis with local treatment. Nevertheless, given the potential metastatic risk, a close follow-up and extensive study is necessary, especially in those with aggressive pathological factors such as deep infiltration or high-histological-grade.