Benign Ovarian Tumors and Endometriosis [106]

INTRODUCTION: Endometriosis is a common gynecologic disorder characterized by the presence of ectopic endometrial glands and stroma. Although endometriosis is considered a benign condition, malignant transformation of endometriosis has been reported. We report our findings on the association between endometriosis and different benign neoplastic ovarian histology. METHODS: We retrospectively analyzed a prospectively maintained database, from July 2008 to April 2013, to extract cases with final pathology consistent with benign ovarian histology and the presence of biopsy-proven endometriosis. The histologic subtype of benign ovarian neoplasm in the presence of endometriosis was tabulated. RESULTS: Among the 228 patients analyzed with a preoperative diagnosis of a pelvic mass, there were a total of 338 cysts. There were 174 (51%) neoplastic cysts of which 43 (25%) had biopsy-proven endometriosis. After adjusting for age and body mass index, patients with benign epithelial cysts were more likely to have endometriosis than patients with benign germ cell histology (prevalence ratio 1.89, confidence interval 1.04–3.44; P<.038). However, when comparing benign epithelial with sex cord stromal tumors, endometriosis was not found to be statistically prevalent (P<.518). CONCLUSION: The frequency of endometriosis in women is still debated. This further complicates the evaluation of the frequency of association between endometriosis and different benign tumor histology. Our data show endometriosis having a prevalence of 25% in patients with neoplastic cysts. Furthermore, endometriosis is more likely associated with benign epithelial type histology rather than germ cell tumors.