Progression to pseudomyxoma peritonei in patients with low grade appendiceal mucinous neoplasms discovered at time of appendectomy

• Published in: The American journal of surgery Vol. 223; no. 6; pp. 1183 - 1186
• Main Authors: Reiter, Shelby, Rog, Colin J., Alassas, Mohamed, Ong, Evan
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01.06.2022; Elsevier Limited
• Subjects: Appendectomy; Appendiceal cancer; Appendiceal neoplasm; Appendiceal tumor; Appendicitis; Appendix; Asymptomatic; Biomarkers; Cancer; Data analysis; Demographic variables; Epithelium; Gastrointestinal cancer; Laparoscopy; Low grade appendiceal mucinous neoplasm; Medical referrals; Mucin; Neoplasms; Pathology; Patients; Pseudomyxoma peritonei; Surgery; Surveillance; Tumors; Low grade appendiceal mucinous neoplasm; Appendectomy; Appendiceal cancer; Appendiceal tumor; Pseudomyxoma peritonei; Appendiceal neoplasm
• ISSN: 0002-9610; 1879-1883
• DOI: 10.1016/j.amjsurg.2021.12.003

The discovery of a low grade appendiceal mucinous neoplasm (LAMN) during appendectomy is a rare scenario. These neoplasms can progress to pseudomyxoma peritonei (PMP), however the incidence of progression is not well known. The records of all patients with a diagnosis of localized LAMN found during appendectomy were identified, and demographic, tumor, surveillance, and outcome variables were analyzed. Progression to PMP occurred in 20% of patients in an average of 12.4 months after appendectomy with median follow-up of 18 months. Tumor variables such as margin positivity, appendiceal perforation, and presence of extra-appendiceal acellular mucin or mucinous epithelium on the serosal were not significantly associated with progression. During an average follow-up period of 18 months after surgery, progression to PMP occurred in a fifth of patients. It is difficult to predict which patients will progress, therefore cross-sectional imaging surveillance is recommended for all patients. •Low grade appendiceal mucinous neoplasms (LAMN) are among the most common appendiceal tumors.•In this series, LAMN progressed to pseudomyxoma peritonei (PMP) in 20% of patients in an average of 1 year.•In this series, positive proximal appendiceal margin and perforation did not correlate with increased progression risk.•Surveillance imaging is recommended for all patients.