Abstract: Objective To assess the clinical and pathological features of pseudomyxoma peritonei(PMP). Methods Clinical,pathological and follow-up data about 92 PMP patients admitted to our hospital were retrospectively analyzed.The patients were divided into disseminated peritoneal adenomucinosis(DPAM) group(n=49),peritoneal mucinous carcinomatosis(PMCA) group(n=17),and PMCA with intermediate or discordant features(PMCA-I/D) group(n=26).Their survival rate was calculated with the Kaplan-Meier method and related factors for their prognosis were analyzed. Results Twenty-two of the 92 PMP patients died at the mean age of 51.9 years(22-76 years) with a median survival time of 124.0 months and their 3-,5-,and 10-year survival rate was 74.0%,67.0% and 49.0%,respectively.Eight patients in DPAM group died with a median survival time of 312.9 months and their 3-,5-,and 10-year survival rate was 97.0%,80.0%,and 67.0%,respectively.Six patients in PMCA-I/D group died with a median survival time of 84.0 months and their 3-,5-,and 10-year survival rate was 80.0%,67.0%,and 50.0%,respectively.Eight patients in PMCA group died with a median survival time of 31.7 months and their 3-and 5-year survival rate was 65.0% and 28.0%,respectively.The longest follow-up time was 108 months with the best prognosis observed in DPAM group and the poorest prognosis observed in PMCA group(P=0.001).The survival time of the patients,especially those with their age <40 years,was closely related with their age,appendiceal tumor and parenchymal organ involvement. Conclusion PMP should be used as DPAM,PMCA and PMCA-I/D in its pathological diagnosis.Although the pathological morphology of most PMP patients is benign or low malignant,their 10-year survival rate is rather low.The prognosis of PMP patients,especially those with their age <40 years,is closely related with their age,appendiceal tumor and parenchymal organ involvement.