Appendiceal mucinous neoplasms: Optimizing treatment strategies based on clinical, histological, and molecular features

Sep 24, 2026

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Appendiceal mucinous neoplasms (AMNs) are rare tumors arising from mucin-producing epithelial cells of the appendix, showing benign or malignant behavior. Often detected incidentally during appendectomy, they range from asymptomatic cases to presentations resembling acute appendicitis. Histology distinguishes low-grade (LAMNs) and high-grade (HAMNs) noninvasive lesions and invasive mucinous adenocarcinomas; rupture can cause pseudomyxoma peritonei (PMP). Management relies on surgical resection and intraoperative assessment to prevent rupture, with treatment selection including appendectomy, right hemicolectomy, and cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy, supported by mucin detection, immunohistochemistry, and molecular profiling (e.g., KRAS, GNAS, TP53).

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CategoryHealthcare

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Appendiceal mucinous neoplasms: Optimizing treatment strategies based on clinical, histological, and molecular features

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| W | J | C | O | World Journal of
Clinical Oncology | | --- | --- | --- | --- | --- | Submit a Manuscript: [https://www.f6publishing.com](https://www.f6publishing.com) World J Clin Oncol 2025 August 24; 16(8): 109088 DOI: 10.5306/wjco.v16.i8.109088 ISSN 2218-4333 (online) MINIREVIEWS Appendiceal mucinous neoplasms: Optimizing treatment strategies based on clinical, histological, and molecular features Atsushi Mitamura, Shingo Tsujinaka, Fumiyoshi Fujishima, Kentaro Sawada, Makoto Hikage, Tomoya Miura, Yoh Kitamura, Yuuri Hatsuzawa, Toru Nakano, Chikashi Shibata Specialty type: Oncology Provenance and peer review: Invited article; Externally peer reviewed. Peer-review model: Single blind Peer-review report’s classification Scientific Quality: Grade B Novelty: Grade B Creativity or Innovation: Grade B Scientific Significance: Grade B P-Reviewer: Liu J Received: April 29, 2025 Revised: June 3, 2025 Accepted: July 16, 2025 Published online: August 24, 2025 Processing time: 113 Days and 15.5 Hours 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 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](tsujinakas@tohoku-mpu.ac.jp) 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 ATrich 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. Key Words: Low-grade appendiceal neoplasms; High-grade appendiceal neoplasms; Mucinous adenocarcinomas; Pseudomyxoma peritonei; Immunohistochemistry; Molecular WJCO [https://www.wjgnet.com](https://www.wjgnet.com) 1 August 24, 2025 Volume 16 Issue 8 Mitamura A et al. Treatment strategies for AMNs markers; Cytoreductive surgery; Hyperthermic intraperitoneal chemotherapy ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved. 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-grad

FAQs

What are appendiceal mucinous neoplasms (AMNs) and how are they commonly found?

AMNs are rare tumors from mucin-producing epithelial cells of the appendix. They are often discovered incidentally during appendectomy and may be asymptomatic or mimic acute appendicitis.

How are AMNs classified histologically?

Noninvasive AMNs are classified as low-grade (LAMNs) or high-grade (HAMNs), while invasive tumors are categorized as mucinous adenocarcinomas.

Why is rupture clinically important in AMNs, and what treatments are used?

Rupture can lead to pseudomyxoma peritonei (PMP). Surgical resection is the primary approach, with intraoperative assessment to prevent rupture; options include appendectomy, right hemicolectomy, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

Sep 24, 2026

Uploaded by Ben