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World J Gastroenterol. Apr 7, 2022; 28(13): 1304-1314
Published online Apr 7, 2022. doi: 10.3748/wjg.v28.i13.1304
Management of incidentally discovered appendiceal neuroendocrine tumors after an appendicectomy
José Luis Muñoz de Nova, Jorge Hernando, Miguel Sampedro Núñez, Greissy Tibisay Vázquez Benítez, Eva María Triviño Ibáñez, María Isabel del Olmo García, Jorge Barriuso, Jaume Capdevila, Elena Martín-Pérez
José Luis Muñoz de Nova, Elena Martín-Pérez, Department of General and Digestive Surgery, Hospital Universitario de La Princesa, Madrid 28006, Spain
José Luis Muñoz de Nova, Elena Martín-Pérez, Department of Surgery, Universidad Autónoma de Madrid, Madrid 28029, Spain
Jorge Hernando, Jaume Capdevila, Gastrointestinal and Endocrine Tumor Unit, Medical Oncology Department, Vall d´Hebron University Hospital, Vall d´Hebron Institute of Oncology, Barcelona 08035, Spain
Miguel Sampedro Núñez, Department of Endocrinology and Nutrition, Hospital Universitario de La Princesa, Madrid 28006, Spain
Greissy Tibisay Vázquez Benítez, Department of Pathology, Hospital Universitario Puerta de Hierro, Madrid 28222, Spain
Greissy Tibisay Vázquez Benítez, Department of Pathology, Universidad Autónoma de Madrid, Madrid 28029, Spain
Eva María Triviño Ibáñez, Department of Nuclear Medicine, Virgen de las Nieves University Hospital, Granada 18014, Spain
María Isabel del Olmo García, Department of Endocrinology and Nutrition, Hospital Universitario i Politècnic La Fe, Valencia 46023, Spain
Jorge Barriuso, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, United Kingdom
Jorge Barriuso, Department of Medical Oncology, The Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom
Author contributions: Muñoz de Nova JL, Hernando J, Sampedro Núñez M, Vázquez Benítez GT, Triviño Ibáñez EM conceived the review and conducted the literature review; Muñoz de Nova JL, Hernando J, Sampedro Núñez M, Vázquez Benítez GT, Triviño Ibáñez EM, del Olmo García MI, Barriuso J analyzed the data and wrote the manuscript; Capdevila J, Martin-Perez E contributed to the design of the paper and carried out a critical review of the text; all authors have read and approve the final manuscript.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: José Luis Muñoz de Nova, MD, PhD, Associate Professor, Surgeon, Department of General and Digestive Surgery, Hospital Universitario de La Princesa, Diego de León, 4th Floor, Madrid 28006, Spain. jmunoz@salud.madrid.org
Received: December 7, 2021
Peer-review started: December 7, 2021
First decision: January 27, 2022
Revised: February 9, 2022
Accepted: February 23, 2022
Article in press: February 23, 2022
Published online: April 7, 2022
Processing time: 112 Days and 20.9 Hours
Abstract

Appendiceal neuroendocrine tumors (aNETs) are an uncommon neoplasm that is relatively indolent in most cases. They are typically diagnosed in younger patients than other neuroendocrine tumors and are often an incidental finding after an appendectomy. Although there are numerous clinical practice guidelines on management of aNETs, there is continues to be a dearth of evidence on optimal treatment. Management of these tumors is stratified according to risk of locoregional and distant metastasis. However, there is a lack of consensus regarding tumors that measure 1-2 cm. In these cases, some histopathological features such as size, tumor grade, presence of lymphovascular invasion, or mesoappendix infiltration must also be considered. Computed tomography or magnetic resonance imaging scans are recommended for evaluating the presence of additional disease, except in the case of tumors smaller than 1 cm without additional risk factors. Somatostatin receptor scintigraphy or positron emission tomography with computed tomography should be considered in cases with suspected residual or distant disease. The main point of controversy is the indication for performing a completion right hemicolectomy after an initial appendectomy, based on the risk of lymph node metastases. The main factor considered is tumor size and 2 cm is the most common threshold for indicating a colectomy. Other factors such as mesoappendix infiltration, lymphovascular invasion, or tumor grade may also be considered. On the other hand, potential complications, and decreased quality of life after a hemicolectomy as well as the lack of evidence on benefits in terms of survival must be taken into consideration. In this review, we present data regarding the current indications, outcomes, and benefits of a colectomy.

Keywords: Neuroendocrine tumors; Carcinoid tumor; Appendiceal neoplasms; Colectomy; Neoplasm grading; Treatment outcome

Core Tip: In this review, we analyze the features to consider when appendiceal neuroendocrine tumor is found after an appendectomy. We critically analyze the main indications for a completion right hemicolectomy and the risk-benefit ratio.