Risk of preoperative understaging of duodenal neuroendocrine neoplasms: a plea for caution in the treatment strategy.

PURPOSE: Pretreatment staging is the milestone for planning either surgical or endoscopic treatment in duodenal neuroendocrine neoplasms (dNENs). Herein, a series of surgically treated dNEN patients was evaluated to assess the concordance between the pre- and postsurgical staging. METHODS: Retrospective analysis of patients with a histologically confirmed diagnosis of dNENs, who underwent surgical resection observed at eight Italian tertiary referral centers. The presurgical TNM stage, based on the radiological and functional imaging, was compared with the pathological TNM stage, after surgery. RESULTS: From 2000 to 2019, 109 patients were included. Sixty-six patients had G1, 26 a G2, 7 a G3 dNEN (Ki-67 not available in 10 patients). In 46/109 patients (42%) there was disagreement between the pre- and postsurgical staging, being it understaged in 42 patients (38%), overstaged in 4 (3%). As regards understaging, in 25 patients (22.9%), metastatic loco-regional nodes (N) resulted undetected at both radiological and functional imaging. Understaging due to the presence of distal micrometastases (M) was observed in 2 cases (1.8%). Underestimation of tumor extent (T) was observed in 12 patients (11%); in three cases the tumor was understaged both in T and N extent. CONCLUSIONS: Conventional imaging has a poor detection rate for loco-regional nodes and micrometastases in the presurgical setting of the dNENs. These results represent important advice when local conservative approaches, such as endoscopy or local surgical excision are considered and it represents a strong recommendation to include endoscopic ultrasound in the preoperative tools for a more accurate local staging.

Duodenal neuroendocrine neoplasms: a still poorly recognized clinical entity.

BACKGROUND: Duodenal neuroendocrine neoplasms (dNENs) are rare tumors, which usually show good prognosis. The optimal management of these tumors is still far from being clearly understood because of their rarity and the poor level of knowledge about their natural history. Herein, we have reviewed the literature on dNENs to collect and analyze the current data on epidemiology, diagnosis and management of these rare tumors. METHODS: Bibliographical searches were performed in PubMed, using the following keywords: duodenal neuroendocrine neoplasm; duodenum; gastrinoma; diagnosis; therapy; guidelines. We searched for all relevant articles published over the last 15 years. Non-English language papers were excluded. RESULTS: We reviewed the pertinent articles about dNENs. Upper gastrointestinal endoscopy with biopsy is the cornerstone of the dNENs diagnostic process. Endoscopic ultrasound with fine-needle aspiration/biopsy should be performed in order to locally stage the disease and in all cases of non-diagnostic endoscopy. Endoscopic or complete surgical removal of the primary lesion is the recommended treatment and is generally achievable for the majority of the patients. A less aggressive approach may be suggested for well-differentiated low-stage tumors. After NEN removal, patients should be closely followed-up especially during the first 3 years by endoscopic examination, imaging tests and CgA measurements. CONCLUSIONS: The multi-disciplinary approach and the preservation of the quality of life of the patients play a key role in the therapeutic process for dNENs. Further studies are needed to better define standardized guidelines specific to dNENs, including optimal management approaches and follow-up intervals.

Endoscopic Resection for Duodenal Neuroendocrine Neoplasms between 10 and 20 mm-A Systematic Review and Meta-Analysis.

Background. The optimal management of duodenal neuroendocrine neoplasms (dNENs) sized 10-20 mm remains controversial and although endoscopic resection is increasingly performed instead of surgery, the therapeutic approach in this setting is not fully standardized. We performed a systematic review of the literature and a meta-analysis to clarify the outcomes of endoscopic resection for 10-20 mm dNENs in terms of efficacy (i.e., recurrence rate) and safety. Methods. A computerized literature search was performed using relevant keywords to identify pertinent articles published until January 2023. Results. Seven retrospective studies were included in this systematic review. The overall recurrence rate was 14.6% (95%CI 5.4-27.4) in 65 patients analyzed, without significant heterogeneity. When considering studies specifically focused on endoscopic mucosal resection, the recurrence rate was 20.5% (95%CI 10.7-32.4), without significant heterogeneity. The ability to obtain the free margin after endoscopic resection ranged between 36% and 100%. No complications were observed in the four studies reporting this information. Conclusions. Endoscopic resection could be the first treatment option in patients with dNENs sized 10-20 mm and without evidence of metastatic disease. Further studies are needed to draw more solid conclusions, particularly in terms of superiority among the available endoscopic techniques.

Duodenal Gastric Metaplasia and Duodenal Neuroendocrine Neoplasms: More Than a Simple Coincidence?

BACKGROUND: Duodenal gastric metaplasia (DGM) is considered a precancerous lesion. No data are available regarding its possible role as a risk factor for duodenal neuroendocrine neoplasms (dNENs). AIMS: To assess the prevalence of DGM in a cohort of dNENs. METHODS: Subgroup analysis of a retrospective study including dNEN patients who underwent surgical resection between 2000 and 2019 and were observed at eight Italian tertiary referral centers. RESULTS: 109 dNEN patients were evaluated. Signs of DGM associated with the presence of dNEN were reported in 14 patients (12.8%). Among these patients, nine (64.4%) had a dNEN of the superior part of the duodenum, one (7.1%) a periampullary lesion, three (21.4%) a dNEN located in the second portion of the duodenum, with a different localization distribution compared to patients without DGM (p = 0.0332). Ten were G1, three G2, and in one patient the Ki67 was not available. In the group with DGM, six patients (35.7%) were classified at stage I, five (28.6%) at stage II, three (21.4%) at stage III, and no one at stage IV. In the group without DGM, 20 patients (31%) were at stage I, 15 (15%) at stage II, 42 (44%) at stage III, and 19 (20%) at stage IV (p = 0.0236). At the end of the study, three patients died because of disease progression. CONCLUSIONS: our findings might suggest that DGM could represent a feature associated with the occurrence of dNEN, especially for forms of the superior part of the duodenum, which should be kept in mind in the endoscopic follow up of patients with DGM. Interestingly, dNEN inside DGM showed a more favorable staging, with no patients in stage IV. The actual relationship and the clinical relevance of this possible association require further clarification.