Abstract: Objective To analyze the clinicopathological characteristics of appendix pseudomyxoma peritonei in the elderly and the effect of surgical treatment strategy on prognosis. Methods The general data, clinical manifestation, imaging feature, surgical treatment strategies, pathological results and prognosis of 48 elderly patients with appendix pseudomyxoma peritonei were analyzed retrospectively. Results Among the 48 patients, 38 presented with unruptured tumors (unruptured tumor group) and 10 presented with ruptured tumors during the surgery (ruptured tumor group). There were no significant differences in age, gender, tumor markers, clinical manifestation and tumor diameter between the two groups (P>0.05). There were 5 patients with malignant tumor in unruptured tumor group and 6 patients with malignant tumor in ruptured tumor group, and the difference between the two groups was statistically significant (P<0.05). This study was followed up for 13 to 101 months (mean 34 months), and no patient died during the follow-up period. In unruptured tumor group, 8 patients recurred within one year after surgery, including 5 patients who were initially diagnosed as malignant tumor; Within three years after surgery, 10 patients recurred and all of them underwent secondary surgery, and 3 patients who were initially diagnosed as benign transformed to malignant. All the patients in unruptured tumor group had no recurrence within 3 years after surgery. The risk of recurrence and malignant transformation in ruptured tumor group were significantly higher than those in unruptured tumor group (P<0.05). Conclusions Complete resection is key to the treatment of elderly patients with appendiceal pseudomyxoma peritonei. The tumor is more prone to malignant transformation and recurrence after rupture, and the patients rarely benefit from chemotherapy.

Key words: appendix pseudomyxoma peritonei, pseudomyxoma peritonei, intraperitoneal chemotherapy, aged