[Mucocele of the appendix]

INTRODUCTION: Mucoceles of the appendix are infrequent entities and are found in only 0.25% of all appendectomies and 8% of all appendicular tumors. MATERIAL AND METHODS: We describe 27 cases of mucocele of the appendix treated at Donostia Hospital between January 1978 and December 2006. RESULTS: The mean age of the patients was 54.4 +/- 21.7 years (range: 17-88). Of the 27 patients, 15 (55.5%) were males and 12 (44.5%) were females. Emergency surgery was performed in 17 patients (62.9%). Mucoceles were identified as operative findings during surgery for other reasons in seven patients (25.9%). Three patients (11.1%) underwent surgery because of a diagnosis of abdominal tumor. The main reason for emergency surgery was lower right abdominal pain in 14 patients (82.2%), intestinal obstruction in one (5.8%), a diagnosis of endometriosis in one (5.8%) and a diagnosis of pyosalpinx in one (5.8%). Three patients underwent surgery due to pseudomyxoma peritonei after 24, 36 and 41 months' follow-up. The third patient is asymptomatic after peritonectomy and a follow-up of 78 months. We found an overall incidence of 11 cases (40.7%) presenting with synchronous or metachronous neoplasms from other locations. CONCLUSIONS: We recommend monitoring of all patients with mucocele of the appendix, because these masses can sometimes be associated with neoplasms in other locations and there is a risk of pseudomyxoma peritonei even after a long follow-up.