{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T21:48:36Z","timestamp":1775166516397,"version":"3.50.1"},"reference-count":18,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T00:00:00Z","timestamp":1625702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100014892","name":"Aerospace Center Hospital","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100014892","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:sec><jats:title>Objective<\/jats:title><jats:p>To investigate the clinicopathological features and follow-up of low-grade appendiceal mucinous neoplasms (LAMNs) confined to the appendix.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The clinicopathological features, pathological primary tumor (pT) staging and follow-up of 22 patients with LAMNs confined to the appendix were analyzed retrospectively.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Of 22 patients with LAMNs, 14 were pTis (eight pTis<jats:sup>m<\/jats:sup> and six pTis<jats:sup>f<\/jats:sup>), six were pT3, and two were pT4a. The appendiceal diameter was significantly larger for pTis<jats:sup>f<\/jats:sup> than for pTis<jats:sup>m<\/jats:sup>. The interval between first symptoms and surgery was longer for pTis<jats:sup>f<\/jats:sup> than for pTis<jats:sup>m<\/jats:sup>, but not significantly different. No significant differences were found between the pT stages and appendiceal diameter or in the interval between the first symptoms and surgery. Pathomorphologically, the epithelial structures were mainly flat (100%), undulating or scalloped (82%); a few showed filiform villous hyperplasia (46%), and seven (32%) had serrated lesions in the background. Diverticula may be associated with LAMNs, and the location of acellular mucin caused by diverticula affected the pT stage of the LAMNs. The immunohistochemistry information showed the same pattern with cytokeratin 7 (CK7) negative, cytokeratin 20 (CK20) positive and caudal type homeobox 2 (CDX-2) positive. No lymph node metastasis was found. The lack of treatment guidelines for LAMNs confined to the appendix and different acceptances of patients of preventive intervention led to varied clinical treatments. However, we found no short-term benefits of prophylactic extended resection or hyperthermic intraperitoneal chemotherapy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>LAMNs confined to the appendix are rare and must be differentiated from serrated lesions and diverticula. LAMNs with different pT stages have inert biological behavior. Determining the long-term effects of preventive treatment on survival and recurrence requires more data and a longer follow-up.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fonc.2021.696846","type":"journal-article","created":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T07:00:36Z","timestamp":1625727636000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Clinicopathological Features of Low-Grade Appendiceal Mucinous Neoplasms Confined to the Appendix"],"prefix":"10.3389","volume":"11","author":[{"given":"Yiyan","family":"Lu","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fang","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruiqing","family":"Ma","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lan","family":"Fang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Changhai","family":"Qi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2021,7,8]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"291","DOI":"10.1097\/01.pap.0000194625.05137.51","article-title":"Appendiceal Mucinous Tumors and Pseudomyxoma Peritonei: Histologic Features, Diagnostic Problems, and Proposed Classification","volume":"12","author":"Pai","year":"2005","journal-title":"Adv Anat Pathol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1007\/978-0-387-48993-3_5","article-title":"Pseudomyxoma Peritonei Syndrome: Classification of Appendiceal Mucinous Tumours","volume":"134","author":"Pai","year":"2007","journal-title":"Cancer Treat Res"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-199512000-00006","article-title":"Disseminated Peritoneal Adenomucinosis and Peritoneal Mucinous Carcinomatosis. A Clinicopathologic Analysis of 109 Cases With Emphasis on Distinguishing Pathologic Features, Site of Origin, Prognosis, and Relationship to \u201cPseudomyxoma Peritonei\u201d","volume":"19","author":"Ronnett","year":"1995","journal-title":"Am J Surg Pathol"},{"key":"B4","volume-title":"WHO Classification of Tumours of the Digestive System","author":"Carr","year":"2010"},{"key":"B5","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1097\/PAS.0000000000000535","article-title":"Peritoneal Surface Oncology Group International. A Consensus fors Classification and Pathologic Reporting of Pseudomyxoma Peritonei and Associated Appendiceal Neoplasia: The Results of the Peritoneal Surface Oncology Group International (PSOGI) Modified Delphi Process","volume":"40","author":"Carr","year":"2016","journal-title":"Am J Surg Pathol"},{"key":"B6","volume-title":"WHO Classification of Tumours of the Digestive System","author":"Misdragi","year":"2019"},{"key":"B7","doi-asserted-by":"crossref","DOI":"10.1007\/978-3-319-40618-3_19","article-title":"Appendix\u2013carcinoma. In : American Joint Committeeon Cancer","volume-title":"AJCC Cancer Staging Manual","author":"Overman","year":"2017"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e3181af6067","article-title":"Appendiceal Mucinous Neoplasms: Clinicopathologic Study of 116 Cases With Analysis of Factors Predicting Recurrence","volume":"33","author":"Pai","year":"2009","journal-title":"Am J Surg Pathol"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1016\/j.humpath.2017.09.005","article-title":"Grading and Staging Mucinous Neoplasms of the Appendix: A Case Series and Review of the Literature","volume":"69","author":"Umetsu","year":"2017","journal-title":"Hum Pathol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1177\/1066896919883679","article-title":"Low-Grade Appendiceal Mucinous Neoplasms: A Single Institution Experience of 64 Cases With Clinical Follow-Up and Correlation With the Current (Eighth Edition) AJCC Staging","volume":"28","author":"Mary","year":"2020","journal-title":"Int J Surg Pathol"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1177\/0003134820964464","article-title":"Predictors of Progression of Appendiceal Mucinous Neoplasm to Pseudomyxoma Peritonei","volume":"86","author":"Sueda","year":"2020","journal-title":"Am Surg"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.path.2020.05.006","article-title":"Updates in Appendix Pathology The Precarious Cutting Edge","volume":"13","author":"Norman","year":"2020","journal-title":"Surg Pathol Clin"},{"key":"B13","doi-asserted-by":"publisher","first-page":"89","DOI":"10.3969\/J.ISSN.1007-8096.2020.05.001","article-title":"Update and Progress of Classification of Appendiceal Tumors","volume":"27","author":"Lu-ping","year":"2020","journal-title":"J\u00a0Diag Pathol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0000000000001551","article-title":"Clinicopathologic Features of Low-Grade Appendiceal Mucinous Neoplasm A Single-Institution Experience of 117 Cases","volume":"44","author":"Phoenix","year":"2020","journal-title":"Am J Surg Pathol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.3760\/CMA.J.CN112151-20191231-00840","article-title":"Appendiceal Diverticulosis, a Potential Mimic of Low Grade Appendiceal Mucinous Neoplasm: Analysis of 20 Cases","volume":"49","author":"Wang","year":"2020","journal-title":"Chin J\u00a0Pathol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31817ec31e","article-title":"Prognostic Significance of Localized Extraappendiceal Mucin Deposition in Appendiceal Mucinous Neoplasms","volume":"33","author":"Yantiss","year":"2009","journal-title":"Am J Surg Pathol"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1016\/j.amjsurg.2019.07.035","article-title":"Role of Right Hemicolectomy in Patients With Low-Grade Appendiceal Mucinous Adenocarcinoma","volume":"218","author":"Nasseri","year":"2019","journal-title":"Am J Surg"},{"key":"B18","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1097\/MD.0000000000022071","article-title":"Comparative Effectiveness of Prophylactic Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Resected Low-Grade Appendiceal Mucinous Neoplasm (LAMN)","volume":"99","author":"Yang","year":"2020","journal-title":"Medicine"}],"container-title":["Frontiers in Oncology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2021.696846\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T07:00:44Z","timestamp":1625727644000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fonc.2021.696846\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,7,8]]},"references-count":18,"alternative-id":["10.3389\/fonc.2021.696846"],"URL":"https:\/\/doi.org\/10.3389\/fonc.2021.696846","relation":{},"ISSN":["2234-943X"],"issn-type":[{"value":"2234-943X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,7,8]]},"article-number":"696846"}}