Does a Positive Appendiceal Resection Margin in Low-Grade Appendiceal Mucinous Neoplasms, Warrant Additional Surgery? Our Institution Experience and Literature Review.

Abstract

BACKGROUND: Management of low-grade appendiceal mucinous neoplasm (LAMN) with positive resection margin is controversial. Some guidelines recommend surgical reexcision, whereas others recommend a conservative approach. The purpose of our study was to determine whether involvement of the resection margin by LAMN is a risk factor for local recurrence requiring additional surgery. DESIGN: This is a retrospective study (January 2000-December 2020) of uncomplicated LAMNs with neoplastic epithelium or dissecting mucin at the resection margin. For cases treated with additional surgery, the presence of residual tumor was evaluated. Clinical follow-up was attained in all cases. We also conducted a literature review. RESULTS: The study investigated 98 patients. Eight with median age of 67 (range: 45-91) years had a LAMN involving the resection margin (8.2%). Five of eight LAMNs (62.5%) with neoplastic epithelium at the margin underwent surgery, and no residual neoplasm was identified. The other three cases were followed conservatively, and no patient developed recurrence (follow-up: 18-69 months with a mean of 45 months). In a review of the literature, we identified 52 LAMNs with positive margin. Although three cases had acellular mucin and one residual LAMN in the reexcision specimen (7.7%), neither of these four cases or any of the other 46 followed conservatively had recurrence of disease. CONCLUSIONS: These data suggest that for patients with uncomplicated LAMN confined to the appendix, the involvement of the appendiceal margin does not necessary lead to recurrence of LAMN, and a conservative management is a reasonable alternative.