[Mucocele of the appendix]

Mucoceles of the appendix are infrequent entities and are found in only 0.25% of all appendectomies and 8% of all appendicular tumors.

We describe 27 cases of mucocele of the appendix treated at Donostia Hospital between January 1978 and December 2006.

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.

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.