Should we remove the normal-looking appendix during operations for borderline mucinous ovarian neoplasms?: A retrospective study of 129 cases

•If the appendix is grossly normal appendiceal neoplasms are not expected.•Appendectomy does not provide any advantage on survival of patients with mBOT.•No recurrence was detected in women who did not undergo appendectomy.•Routine appendectomy is controversial due to potential complications.

IntroductionThe aim of this study was to determine how often the appendix is involved or the primary source of cancer in women undergoing surgery for mucinous borderline ovarian tumour (mBOT) or invasive mucinous ovarian tumour (IMOT) and to evaluate whether appendectomy is necessary.MethodsThe hospital database was searched for women who underwent surgery and whose final diagnosis was mBOT, IMOT or mucinous appendix carcinoma between 1998 and 2014.ResultsOne hundred and twenty-nine cases were identified, including 69 mBOT, 51 IMOT and nine primary mucinous appendix carcinomas. Of 97 appendectomies performed, nine lymphoid hyperplasia, two mucocele, one carcinoid tumour of the appendix, one mucinous tumour metastasis from the ovary and nine primary mucinous appendix carcinomas were found and all appendices were grossly abnormal. No recurrence was seen during the follow-up period in 28 patients who had no appendectomy performed for grossly normal appendix. Pathologic diagnosis was normal in all 65 patients whose appendix was noted to be grossly normal and who underwent appendectomy. No recurrence was detected during a median follow-up period of 7 years (range 1–16 years).Sensitivity, specificity, positive and negative predictive value of the macroscopic appearance of the appendix were 100%, 86.67%, 56.52% and 100.00%, respectively.DiscussionIf the appendix is grossly normal, it appears unnecessary to perform an appendectomy in patients operated for an adnexal mass and whose frozen section analysis was reported as mBOT or IMOT.ConclusionAppendectomy should not be performed if the appendix is grossly normal.