Ultimate Clinical Outcomes of Appendiceal Mucinous Neoplasm of Uncertain Malignant Potential

Background The clinical outcome of appendiceal mucinous neoplasm (AMN) is not well understood. This study aimed to compare the long-term outcome for the uncertain malignant potential (UMP) subtype of AMNs with those of the mucinous adenoma (MA) and mucinous adenocarcinoma (MAC) subtypes. Methods In this study, AMNs were classified into three groups (MA, UMP, and MAC), and clinical characteristics, overall survival (OS), and progression-free survival (PFS) were compared among the three groups. Results The study included 65 AMN patients (26 MA, 20 UMP, and 19 MAC patients). The median follow-up period was 87 months (range 0.3–311.0) months. The symptoms at diagnosis and the presence of pseudomyxoma peritonei were more common in the MAC group than in the MA group ( P = 0.012) or the UMP group ( P