Mitamura A, Tsujinaka S, Fujishima F, Sawada K, Hikage M, Miura T, Kitamura Y, Hatsuzawa Y, Nakano T, Shibata C. Appendiceal mucinous neoplasms: Optimizing treatment strategies based on clinical, histological, and molecular features. World J Clin Oncol 2025; 16(8): 109088 [DOI: 10.5306/wjco.v16.i8.109088]
Corresponding Author of This Article
Shingo Tsujinaka, MD, Associate Professor, Division of Gastroenterologic Surgery, Department of Surgery, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai 983-8536, Miyagi, Japan. tsujinakas@tohoku-mpu.ac.jp
Research Domain of This Article
Gastroenterology & Hepatology
Article-Type of This Article
Minireviews
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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: http://creativecommons.org/licenses/by-nc/4.0/
Atsushi Mitamura, Shingo Tsujinaka, Kentaro Sawada, Makoto Hikage, Tomoya Miura, Yoh Kitamura, Yuuri Hatsuzawa, Toru Nakano, Chikashi Shibata, Division of Gastroenterologic Surgery, Department of Surgery, Tohoku Medical and Pharmaceutical University, Sendai 983-8536, Miyagi, Japan
Fumiyoshi Fujishima, Department of Pathology, Tohoku Medical and Pharmaceutical University, Sendai 983-8536, Miyagi, Japan
Author contributions: Mitamura A and Tsujinaka S contributed to conception and design of the study; Mitamura A, Tsujinaka S, Fujishima F, Sawada K, and Hikage M contributed to acquisition of the data; Mitamura A, Fujishima F, Miura T, Kitamura Y, and Hatsuzawa Y contributed to interpretation of the data; Mitamura A and Tsujinaka S drafted the manuscript; Nakano T and Shibata C provided critical review of the manuscript for important intellectual content; all authors read and approved the final version of the manuscript.
Conflict-of-interest statement: The authors declare no conflicts of interest.
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: Shingo Tsujinaka, MD, Associate Professor, Division of Gastroenterologic Surgery, Department of Surgery, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai 983-8536, Miyagi, Japan. tsujinakas@tohoku-mpu.ac.jp
Received: April 29, 2025 Revised: June 3, 2025 Accepted: July 16, 2025 Published online: August 24, 2025 Processing time: 113 Days and 15.7 Hours
Abstract
Appendiceal mucinous neoplasms (AMNs) are rare tumors originating from mucin-producing epithelial cells of the appendix. They can exhibit both benign and malignant behavior. They are often incidentally discovered during appendectomy. Clinical presentation ranges from asymptomatic to mimicking acute appendicitis. Histologically, noninvasive AMNs are classified as low-grade AMNs (LAMNs) or high-grade AMNs (HAMNs), whereas invasive tumors are categorized as mucinous adenocarcinomas. Although LAMNs and HAMNs are generally nonmalignant, rupture can lead to pseudomyxoma peritonei (PMP). Surgical resection is the primary diagnostic and therapeutic approach, with intraoperative assessment to prevent rupture. Treatment strategies vary based on findings and include appendectomy, right hemicolectomy, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. Histological diagnosis relies on mucin detection, and immunohistochemical markers such as cytokeratin 20 (diffusely positive), cytokeratin 7 (often negative), mucin 5AC, and special AT-rich sequence-binding protein 2 assist in characterization. Molecular profiling frequently identifies KRAS, GNAS, and TP53 mutations. KRAS mutations are generally associated with a favorable prognosis, whereas GNAS and TP53 mutations correlate with poorer survival outcomes. These findings highlight the potential role of molecular profiling in guiding treatment strategies for AMN and PMP.
Core Tip: Appendiceal mucinous neoplasms (AMNs) are rare tumors originating in mucin-producing epithelial cells of the appendix. They can be benign or malignant. AMN is often discovered during appendectomy, presenting asymptomatically or mimicking acute appendicitis. Noninvasive AMNs include low-grade and high-grade lesions, whereas invasive types are mucinous adenocarcinomas. Rupture may lead to pseudomyxoma peritonei (PMP). Surgery is the primary treatment, with options including appendectomy, hemicolectomy, or cytoreductive surgery with chemotherapy. Histological diagnosis involves mucin detection and immunohistochemistry markers. Molecular profiling has revealed mutations in KRAS (favorable prognosis) and GNAS and TP53 (poor prognosis), guiding treatment strategies for AMN and PMP.
