{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T16:28:59Z","timestamp":1781195339652,"version":"3.54.1"},"reference-count":22,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2024,9,12]],"date-time":"2024-09-12T00:00:00Z","timestamp":1726099200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Histopathology"],"published-print":{"date-parts":[[2025,1]]},"abstract":"<jats:sec><jats:title>Aims<\/jats:title><jats:p>Neuroendocrine tumours (NETs) occurring in the extrahepatic biliary system are exceedingly rare. While NETs typically manifest as mass lesions, the occurrence of microscopic neuroendocrine cell proliferation without a distinct mass remains undocumented at this location. This study aims to characterise the clinicopathological features of a series of well\u2010differentiated neuroendocrine lesions involving the extrahepatic biliary tree, including mass forming NETs and microscopic non\u2010mass\u2010forming neuroendocrine cell proliferation, designated neuroendocrine cell micronests (NCMs).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods and results<\/jats:title><jats:p>Surgical resections of NETs\/NCMs involving the extrahepatic bile ducts and gallbladder were identified from electronic pathology databases among seven institutions spanning from January 2011 to September 2023. Clinical and histological findings were recorded. Ten patients (four female, six male: age range\u2009=\u200934\u201375\u2009years) were included in the study. Histopathological examination revealed visible mass\u2010forming lesions in four cases (1.6\u201314.0\u2009cm in size), identified in the gallbladder (<jats:italic>n<\/jats:italic>\u2009=\u2009two) or extrahepatic bile duct (<jats:italic>n<\/jats:italic>\u2009=\u2009two), all diagnosed as well\u2010differentiated NETs. The remaining six cases revealed incidental non\u2010mass\u2010forming NCMs in either the cystic duct (<jats:italic>n<\/jats:italic>\u2009=\u2009two), common bile duct (<jats:italic>n<\/jats:italic>\u2009=\u2009three) or gallbladder (<jats:italic>n<\/jats:italic>\u2009=\u2009one), ranging from &lt;\u20090.1 to 0.4\u2009cm; four were associated with biliary lithiasis. No evidence of metastasis or recurrence was seen in the follow\u2010up period (range\u2009=\u20090.1\u201311.2\u2009years).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>This study highlights the spectrum of extrahepatic biliary well\u2010differentiated neuroendocrine lesions, ranging from incidental microscopic NCMs to grossly apparent mass\u2010forming NETs, potentially requiring different clinical management. Noteworthy is the frequent association of incidental microscopic neuroendocrine cell proliferations with biliary lithiasis, indicating a potential neuroendocrine metaplastic pathogenesis that merits further exploration.<\/jats:p><\/jats:sec>","DOI":"10.1111\/his.15316","type":"journal-article","created":{"date-parts":[[2024,9,13]],"date-time":"2024-09-13T03:49:20Z","timestamp":1726199360000},"page":"285-293","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Spectra of well\u2010differentiated neuroendocrine lesions in the extrahepatic biliary system: a case series"],"prefix":"10.1111","volume":"86","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-0918-1816","authenticated-orcid":false,"given":"Yongjun","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Laboratory Medicine and Pathology University of Washington Medical Center  Seattle WA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6029-0124","authenticated-orcid":false,"given":"Ashwini K","family":"Esnakula","sequence":"additional","affiliation":[{"name":"Department of Pathology The Ohio State University Wexner Medical Center  Columbus OH USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8710-5264","authenticated-orcid":false,"given":"Shilpa","family":"Jain","sequence":"additional","affiliation":[{"name":"Department of Pathology Baylor College of Medicine  Houston TX USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2094-0262","authenticated-orcid":false,"given":"Jingmei","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, School of Medicine Indiana University  Indianapolis IN USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1121-267X","authenticated-orcid":false,"given":"Nicole","family":"Panarelli","sequence":"additional","affiliation":[{"name":"Department of Pathology Albert Einstein College of Medicine, Montefiore Medical Center  New York NY USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9293-4801","authenticated-orcid":false,"given":"Sergey","family":"Pyatibrat","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine Royal Columbian Hospital, University of British Columbia  New Westminster BC Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0351-2859","authenticated-orcid":false,"given":"Dipti M","family":"Karamchandani","sequence":"additional","affiliation":[{"name":"Department of Pathology UT\u00a0Southwestern Medical Center  Dallas TX USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,9,12]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/cncr.11105"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijscr.2016.11.043"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1007\/s12253-014-9808-4"},{"key":"e_1_2_9_5_1","first-page":"3381","article-title":"Neuroendocrine tumors of the gallbladder","volume":"19","author":"Niu C","year":"2020","journal-title":"Oncol. 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Rep."},{"key":"e_1_2_9_23_1","first-page":"237","article-title":"Pattern of gastric endocrine cells in microcarcinoidosis\u2014an immunohistochemical study of 14 gastric biopsies","volume":"428","author":"Reinecke P","year":"1996","journal-title":"Virchows Arch."}],"container-title":["Histopathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/his.15316","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,12,20]],"date-time":"2024-12-20T13:21:54Z","timestamp":1734700914000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/his.15316"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,12]]},"references-count":22,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2025,1]]}},"alternative-id":["10.1111\/his.15316"],"URL":"https:\/\/doi.org\/10.1111\/his.15316","archive":["Portico"],"relation":{},"ISSN":["0309-0167","1365-2559"],"issn-type":[{"value":"0309-0167","type":"print"},{"value":"1365-2559","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,12]]},"assertion":[{"value":"2024-05-27","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-08-27","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-09-12","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}