Clinical Case Summary
Gastrointestinal neuroendocrine tumours (NETs) are low-grade malignant tumours in the GI tract. They account for 0.4% to 1.8% of GI malignancies. Duodenal NETs are relatively rare tumours and only accounts for 2% to 3% of GI NETs.
The patient, a 68 year old male, had dyspepsia and OGD showed a 10mm subepithelial lesion (SEL) (Insert image here) in the second part of the duodenum. Biopsies revealed polypoid foveolar hyperplasia. An endoscopic ultrasound (EUS) was done to evaluate the SEL which showed a 7mm x 8mm hypoechoic lesion within the submucosal layer (insert image). There was a slit within the SEL which corresponds to the previous biopsy sampling. Differentials were GIST or pancreatic rest. Further biopsies were taken from the within the slit which concluded as a well-differentiated NET, Grade 1.
PET DOTATE scan showed tracer-avid focus in the duodenum. Chromogranin A was elevated at 1056ug/L.
In view of previous sampling with a biopsy scar now, removal of the duodenal NET was carefully thought out. Endoscopic mucosal resection (EMR) has a higher risk of perforation due to the possibility of fibrosis from the biopsies. Laparoscopic endoscopic cooperative surgery was discussed with the surgeons, however, it is invasive.
Patient then underwent underwater EMR. The duodenal NET had sufficient buoyancy whilst underwater (Insert image). A 10mm snare was used, and polypectomy with Endocut Q mode done with good margins. There was no intraprocedural bleeding nor perforation. Two clips were used to close the polypectomy site prophylactically (Insert image).
Histology demonstrated tumour cells within the lamina propria and submucosa with salt and pepper like chromatin and round nuclei. They were positive for synaptophysin and chromogranin. Ki-67 index was 2%, and the margins were clear. This was conclusive of a NET Grade 1.
This case highlights the approach and differentials to duodenal lesions, and points to be considered for endoscopic resection in the duodenum.
References
Sato Y, Hashimoto S, Mizuno K, Takeuchi M, Terai S. Management of gastric and duodenal neuroendocrine tumors. World J Gastroenterol. 2016 Aug 14;22(30):6817-28
Gaspar JP, Stelow EB, Wang AY. Approach to the endoscopic resection of duodenal lesions. World J Gastroenterol. 2016 Jan 14;22(2):600-17
Wang X, Wu Y, Cao X, Zhang X, Cheng Y, Kong L. Duodenal neuroendocrine tumor: A rare case report. Medicine (Baltimore). 2021 Feb 12;100(6):e24635
Milione M, Parente P, Grillo F, Zamboni G, Mastracci L, Capella C, Fassan M, Vanoli A. Neuroendocrine neoplasms of the duodenum, ampullary region, jejunum and ileum. Pathologica. 2021 Feb;113(1):12-18