Appendiceal tumors in patients undergoing primary surgery for mucinous ovarian tumors in a tertiary hospital, in Southern Thailand

To evaluate the prevalence of appendiceal tumors in patients diagnosed with mucinous ovarian tumors and to determine factors associated with coexisting appendiceal tumors.Retrospective review of all patients who were diagnosed with mucinous ovarian tumors and underwent an appendectomy during surgery between January 2002 and June 2017 was performed. Univariate and multivariate logistic regression analyses were used to identify risk factors for coexisting appendiceal tumors.A total of 303 patients with mucinous ovarian tumors who underwent appendectomy were identified, including 77 (25.4%) mucinous cystadenoma and 226 (74.6%) mucinous borderline tumor or carcinoma. Twenty-one (6.9%) had coexisting appendiceal tumors including 8 that were primary appendiceal mucinous adenocarcinomas, 6 low-grade appendiceal mucinous neoplasms, 6 secondary appendiceal metastasis from the ovary, and one hyperplastic polyp. None of mucinous cystadenoma had coexisting appendiceal tumors. Multivariate analysis revealed advanced age ≥50 years, previous rupture of ovarian tumors, abdominal extension of tumors, and grossly abnormal appendix were independent factors for coexisting appendiceal tumors.Prevalence of coexisting appendiceal tumors in mucinous ovarian tumors was not uncommon. The risk factors were grossly abnormal appendix, abdominal extension of tumor, previous rupture of ovarian tumors, and advanced age.