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

Am J Surg. 2022 Jun;223(6):1183-1186. doi: 10.1016/j.amjsurg.2021.12.003. Epub 2021 Dec 3.


Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Appendectomy; Appendiceal cancer; Appendiceal neoplasm; Appendiceal tumor; Low grade appendiceal mucinous neoplasm; Pseudomyxoma peritonei.

MeSH terms

  • Adenocarcinoma, Mucinous* / pathology
  • Adenocarcinoma, Mucinous* / surgery
  • Appendectomy / adverse effects
  • Appendiceal Neoplasms* / pathology
  • Humans
  • Peritoneal Neoplasms* / pathology
  • Peritoneal Neoplasms* / surgery
  • Pseudomyxoma Peritonei* / diagnosis
  • Pseudomyxoma Peritonei* / pathology
  • Pseudomyxoma Peritonei* / surgery