Duodenal neuroendocrine tumors: what we really know about them? An Italian multicentre experience

Duodenal neuroendocrine neoplasms (dNENs) are heterogeneous tumors and represent up to 3% of all duodenal tumors and 2–3% of all gastrointestinal tumors. Despite clear differences, dNENs have been always treated together with either gastric neuroendocrine tumors or, with pancreatic neuroendocrine tumors, especially if functioning. To date, little has been known about the clinical characteristics, treatment, and prognosis of dNENs, and this kind of neuroendocrine tumor is still largely unexplored. Optimal management of dNENs is still far to be clearly understood, and endoscopic resection is increasingly performed instead of surgery. Surgical resection is generally recommended for ampullary dNENs, regardless of the tumor size, because of its anatomical location and more aggressive behavior compared to those of the non-ampullary type. For non-ampullary forms surgical resection represents the recommended approach to dNENs >20mm in diameter, whereas the value of surgical resection has not been established yet for non- ampullary tumors ≤20mm in diameter. Furthermore, dNENs less than 10mm in diameter and limited to the submucosal layer seem to exhibit a poor tendency to affect lymph nodes or to determine distant metastases, thus they might represent a suitable cluster for endoscopic treatment.

Our Italian multicentre study represents an original study aimed at describing the characteristics, natural history, features, and prognostic factors of these poorly known neoplasms. In this paper, we confirmed dNENs are heterogeneous tumors characterized by highly variable prognosis, that can exhibit aggressive behavior with distant metastases, more frequently than previously described.  In fact, they can be metastatic in up to 54.6% of cases, as observed in our series, either at diagnosis or thereafter, independently of tumor size (median diameter of the lesions in this series was 12 mm, which is very small). As a consequence, surgical resection has been suggested as the preferred treatment modality over endoscopic treatment, also taken into account that dNENs tend to spread to the submucosal layer even during the early stages and the duodenal wall is thinner than the gastric wall with a consequent higher risk of perforation.. Moreover, complete initial staging should be performed before treatment, including nuclear medicine imaging, to exclude distant metastases. Follow-up should be extended to a lifelong horizon.

Further prospective studies are needed to better define standardized guidelines dedicated to dNENs, including optimal patient treatment and management and effective follow-up intervals.

Roberta Elisa Rossi, Sara Massiorni
Gastroenterology and Endoscopy Unit, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico,
Università degli Studi di Milano, Milan, Italy


Heterogeneity of Duodenal Neuroendocrine Tumors: An Italian Multi-center Experience.
Massironi S, Campana D, Partelli S, Panzuto F, Rossi RE, Faggiano A, Brighi N, Falconi M, Rinzivillo M, Delle Fave G, Colao AM, Conte D
Ann Surg Oncol. 2018 Oct


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