Favorable long‐term outcomes of endoscopic resection for nonampullary duodenal neuroendocrine tumor

Abstract

Background and Aim The long‐term outcomes of endoscopic resection for nonampullary duodenal neuroendocrine tumors are limited. We aimed to clarify it. Methods Consecutive patients with nonampullary duodenal neuroendocrine tumors endoscopically treated at our institute between January 2005 and June 2020 were included in this retrospective study. En bloc and R0 resection rates and adverse events were evaluated as short‐term outcomes of endoscopic resection. The 5‐year overall and recurrence‐free survival rates of patients after endoscopic resection were calculated as long‐term outcomes. Results Of 34 patients with 34 lesions, 33 patients (97%) underwent endoscopic mucosal resection, and one (3%) underwent endoscopic submucosal dissection. En bloc resection was achieved in 33 lesions (97%). R0 resection was achieved in 20 lesions (59%). The median tumor size was 6 mm (range: 3–13). Thirty‐one lesions (91%) and three lesions (9%) were classified as G1 and G2, respectively. Lymphovascular invasion was observed in six lesions (18%). Intraprocedural perforation occurred in four patients (12%) who were conservatively treated with endoscopic closure. All 34 patients were followed up without additional treatment after endoscopic resection, and no recurrence or metastasis developed during the median follow‐up period of 47.9 months (range: 9.0–187.1). The 5‐year overall survival and recurrence‐free survival rates were 87.1% and 100%, respectively. Conclusions Endoscopic resection provided a favorable long‐term prognosis for patients with nonampullary duodenal neuroendocrine tumors without lymph node metastasis.

A puzzling case report of well-differentiated neuroendocrine tumor mixed with gastric adenocarcinoma of the fundic gland type associated with autoimmune gastritis

“…On endoscopy, both tumors appeared as submucosal tumors with dilated vessels in the gastric body. 1,5 Histologically, both tumors are composed of small round tumor cells and originate from deep layers. Moreover, recent studies have shed light on the fact that certain GA-FG tumors may exhibit varying degrees of positivity for CD56 and synaptophysin immunohistochemical staining, which have traditionally been employed as the markers of neuroendocrine tumors.…”

Long-term outcomes of endoscopic resection for duodenal neuroendocrine tumors

“…The lower histopathologically complete resection rate compared to the endoscopically complete resection rate could be explained by the difficulty in histopathologically analyzing the horizontal and vertical margins of the resected specimens owing to cauterization artifacts 20 , 21 . Despite the histopathologically incomplete resection state, the electrocauterization effect could destroy remnants of tumor cells in the resection margins with heat generation during endoscopic resection 19 , 22 . The present study investigated the factors associated with histopathologically incomplete resection; the tumor size was the only statistically significant predictive factor for histopathologically incomplete resection.…”

What Every Gastroenterologist Should Know About Gastrointestinal NETs

“…Although there are no specific guidelines, resection is based on tumor size, which correlates with regional LN metastasis. Small (<1 cm), nonampullary, well-differentiated tumors without involvement of the muscularis propria can be endoscopically resected because the risk of LN involvement is low (2%) ( 14 ). Tumors 1–2 cm in size are associated with 4.7% risk of nodal involvement, whereas the risk increases to 20% in duodenal tumors >2 cm ( 15 ).…”

“…Tumors 1–2 cm in size are associated with 4.7% risk of nodal involvement, whereas the risk increases to 20% in duodenal tumors >2 cm ( 15 ). Of note, it is difficult to obtain an R0 resection, which is estimated to be 50%–60% ( 14 , 16 ). After endoscopic resection, if pathology demonstrates positive margins, LVI, or G2/3, surgery referral is appropriate.…”