ObjectiveTo review the experience at the Massachusetts General and Brigham and Women's Hospitals with 23 women treated for pseudomyxoma peritonei between 1961 and 1991.MethodsPatients were identified retrospectively from the tumor registry at the Massachusetts General and Brigham and Women's Hospitals, and all charts were reviewed. The median follow-up interval was 2.5 years (range 3 months to 31 years).ResultsThe mean age at diagnosis was 58 years (range 26–76). Pseudomyxoma peritonei was found in association with ten (44%) ovarian tumors of borderline malignancy, nine (39%) ovarian cystadenocarcinomas, and four (17%) appendiceal cystadenocarcinomas. Three patients had synchronous tumors in the ovary and appendix. All patients underwent surgical staging and cytoreduction. Eleven patients received postoperative therapy and, of these, nine developed a recurrence; 12 patients received no further therapy and, of these, three developed a recurrence. However, these groups were not pathologically comparable. With respect to survival, of the ten patients with borderline malignancies, seven had no evidence of disease, one was alive with disease, and two died of disease. For the nine patients with ovarian cystadenocarcinomas, three had no evidence of disease, one was alive with disease, and five died of disease (median time to death 18 months). For the four patients with appendiceal carcinomas, two had no disease, one was alive with disease, and one died with disease. Among all 23 patients, 12 (52%) developed a recurrence, with a range of time to first recurrence of 3 months to 19 years. Eight women required at least one additional laparotomy because of accumulation of gelatinous material.ConclusionsAlthough pseudomyxoma peritonei is associated with borderline and well-differentiated tumors, recurrence is common and the prognosis after recurrence is guarded. Involvement of the appendix is common; therefore, appendectomy is indicated when pseudomyxoma is encountered. To date, surgery has been the only effective therapy for this disease, and adjuvant therapy has not been shown conclusively to be of benefit.