{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T10:07:48Z","timestamp":1778580468081,"version":"3.51.4"},"reference-count":46,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T00:00:00Z","timestamp":1776988800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Pancreatic neuroendocrine neoplasms (PanNENs) represent a heterogeneous tumor entity with a steadily rising incidence, mainly due to advances in imaging and growing diagnostic awareness. In pancreatic ductal adenocarcinoma (PDAC), the mesopancreas (MP) has been identified as a frequent site of microscopic tumor spread and a key determinant of circumferential resection margin (CRM) status, leading to the concept of standardized mesopancreatic excision (MPE). While its oncological relevance in PDAC is increasingly recognized, the role of the mesopancreas in PanNENs remains unclear. This study aimed to systematically evaluate mesopancreatic infiltration in PanNENs and to identify associated clinicopathological predictors. Methods: Consecutive patients undergoing oncological pancreatoduodenectomy, spleen-preserving distal pancreatectomy, or distal splenopancreatectomy for PanNENs and PanNECs were included. The mesopancreas was histopathologically examined for tumor infiltration within CRM assessment. Results: MP infiltration was detected in 60% of patients. It was associated with higher Ki-67 index, larger tumor size, lymph node involvement, venous invasion, and positive CRM status. A Ki-67 index \u2265 5% and tumor size \u2265 21.5 mm were identified as predictors of MP infiltration. Higher T stage predicted reduced overall survival (OS), whereas MP infiltration, lymphatic (L1) and venous (V1) invasion, and Ki-67 \u2265 5% were associated with impaired disease-free survival (DFS). Conclusions: Mesopancreatic infiltration is frequently present in PanNENs and correlates with aggressive tumor characteristics. Given its association with CRM positivity and reduced DFS, consideration of the mesopancreas in staging and surgical strategies appears oncologically justified. Larger studies are required to validate these findings.<\/jats:p>","DOI":"10.3390\/jcm15093270","type":"journal-article","created":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T11:40:12Z","timestamp":1777981212000},"page":"3270","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Role of the Mesopancreas in Pancreatic Neuroendocrine Neoplasms"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2006-0540","authenticated-orcid":false,"given":"Stephan O.","family":"David","sequence":"first","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ahmad. B.","family":"Sultani","sequence":"additional","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Alexander","sequence":"additional","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sascha","family":"Vaghiri","sequence":"additional","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0554-2402","authenticated-orcid":false,"given":"Irene","family":"Esposito","sequence":"additional","affiliation":[{"name":"Institute of Pathology, Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wolfram T.","family":"Knoefel","sequence":"additional","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9874-9225","authenticated-orcid":false,"given":"Sami A.","family":"Safi","sequence":"additional","affiliation":[{"name":"Department of Surgery (A), Heinrich-Heine-University and University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1053\/j.gastro.2008.05.047","article-title":"Gastrointestinal neuroendocrine tumors: Pancreatic endocrine tumors","volume":"135","author":"Metz","year":"2008","journal-title":"Gastroenterology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3063","DOI":"10.1200\/JCO.2007.15.4377","article-title":"One hundred years after \u201ccarcinoid\u201d: Epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States","volume":"26","author":"Yao","year":"2008","journal-title":"J. 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