Appendectomies are not uncommonly performed following an intraoperative diagnosis of a mucinous ovarian neoplasm, although the evidentiary basis for the practice is relatively limited. The current study is a contemporary re-examination of the issue, based on an analysis of a large single institutional cohort. We assessed whether there are any composite of factors that may be associated with the finding of significant disease in the appendix in this setting following intraoperative consultation (IOC) diagnosis of a mucinous neoplasm on an ovary-based mass. Records for 460 consecutive patients whose ovarian tumors were classified as "mucinous" on IOC (n = 246) and/or permanents (n = 214) were reviewed. The distribution of IOC diagnoses on the 246 tumors were as follows: cystadenoma (114), borderline (55), carcinoma (21), mucinous neoplasm or tumor without definitive classification (53), and probable metastases (3). Appendectomies were performed on 82 (33%) of the 246 cases. In 30 (36%) of these 82 cases, the appendix was grossly normal, the ovarian tumor was unilateral, and there was no intraabdominal/peritoneal disease. Microscopic examination of the appendices in these 30 cases showed no mucinous neoplasms therein, but one case had a grossly inapparent, 4 mm well-differentiated carcinoid. In contrast, among the remaining 52 cases (i.e. those with at least one of the "key abnormal features": intra-abddominal/peritoneal disease and/or appendiceal gross abnormality and/or ovarian tumor bilaterality), 12 neoplasms (23%) were microscopically identified in the appendix (4 adenocarcinomas; 7 LAMN; 1 carcinoid) [p = 0.0256]. Of these 12, a grossly abnormal appendix, intraabdominal/peritoneal disease, and ovarian tumor bilaterality was the sole key abnormal feature in 10, 8 and 4 cases respectively, meaning that requiring that any one feature be present to justify the appendectomy would have missed 17%, 33% and 67% of cases respectively. Only 33% (3/12) cases had all 3 features. Our findings support the emerging body of work that indicates that appendectomies should not be routinely performed during the primary surgery for suspected or confirmed mucinous tumors that involve the ovary, unless there is a specific indication. In our cohort, all identified mucinous appendiceal neoplasms were associated with at least one key abnormal feature (gross abnormalities of the appendix, intraabdominal/peritoneal disease, ovarian tumor bilaterality), which suggests that only in patients that meet these criteria would appendectomies most likely be beneficial.
Keywords: Appendectomy; Appendix; Borderline; Mucinous; Ovary.
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