Management of gastric and duodenal neuroendocrine tumors

Gastrointestinal neuroendocrine tumors (GI-NETs) are rare neoplasms, like all NETs. However, the incidence of GI-NETS has been increasing in recent years. Gastric NETs (G-NETs) and duodenal NETs (D-NETs) are the common types of upper GI-NETs based on tumor location. G-NETs are classified into three distinct subgroups: type I, II, and III. Type I G-NETs, which are the most common subtype (70%-80% of all G-NETs), are associated with chronic atrophic gastritis, including autoimmune gastritis and Helicobacter pylori associated atrophic gastritis. Type II G-NETs (5%-6%) are associated with multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome (MEN1-ZES). Both type I and II G-NETs are related to hypergastrinemia, are small in size, occur in multiple numbers, and are generally benign. In contrast, type III G-NETs (10%-15%) are not associated with hypergastrinemia, are large-sized single tumors, and are usually malignant. Therefore, surgical resection and chemotherapy are generally necessary for type III G-NETs, while endoscopic resection and follow-up, which are acceptable for the treatment of most type I and II G-NETs, are only acceptable for small and well differentiated type III G-NETs. D-NETs include gastrinomas (50%-60%), somatostatin-producing tumors (15%), nonfunctional serotonin-containing tumors (20%), poorly differentiated neuroendocrine carcinomas (< 3%), and gangliocytic paragangliomas (< 2%). Most D-NETs are located in the first or second part of the duodenum, with 20% occurring in the periampullary region. Therapy for D-NETs is based on tumor size, location, histological grade, stage, and tumor type. While endoscopic resection may be considered for small nonfunctional D-NETs (G1) located in the higher papilla region, surgical resection is necessary for most other D-NETs. However, there is no consensus regarding the ideal treatment of D-NETs.

Duodenal neuroendocrine tumor-tertiary care centre experience:A case report

BACKGROUND Neuroendocrine neoplasms(NENs)are a heterogeneous group of neoplasms arising from neuroendocrine cells,which contribute a small fraction of gastrointestinal malignancies.Duodenal neuroendocrine tumors(dNETs)represent 2%of all gastroenteropancreatic NENs.NENs are heterogeneous in terms of clinical symptoms,location,and prognosis.Non-functional NETs are mostly asymptomatic and need a high degree of clinical suspicion.Diagnosis of NETs is by endoscopic,endosonographic biopsy,and histopathological examination with immunohistochemistry staining for synaptophysin and chromogranin A.CASE SUMMARY We present case reports of 5 patients obtained over a period of 10 years in our center with dNETs.One patient had moderately differentiated NET and the remaining four had well-differentiated NET.Surveillance endoscopy was recommended in all the patients and is kept under regular follow-up after performing endoscopic therapy using endoscopic mucosal resection in 4 of them and one patient was advised to undergo a Whipple procedure.CONCLUSION Recently,the number of reported cases of NETs has increased due to advancements in diagnostic modalities and prevalence because of longer survival duration.The management differs based on the site,size,proliferation grade,and locally invasive pattern.They are slow-growing tumors with a good overall prognosis.The prognosis correlates with local lymph node status and metastasis.