Co-Existence of Endometriosis with Ovarian Dermoid Cysts: A Retrospective Cohort Study

Both endometriosis and ovarian dermoid cysts are benign conditions characterized by the presence of well-differentiated tissues in ectopic locations. The presence and surgical excision of these entities can potentially impact ovarian reserves, contributing to reduced chances of future pregnancy. The objective of our study is to investigate the bidirectional association between endometriosis and ovarian dermoid cysts, as well as to analyze the clinical characteristics of patients diagnosed with both conditions. A retrospective cohort study was conducted, including women who underwent laparoscopy and received histological diagnoses of endometriosis and/or dermoid cysts between 2011 and 2019 at the Cantonal Hospital of Schaffhausen. We identified 985 women with endometriosis and 83 women with ovarian dermoid cysts. Among these groups, 22 women presented with both endometriosis and ovarian dermoid cysts. The majority of the above patients had endometriosis stage rASRM I-II (72.7%), with peritoneal endometriosis being the most common phenotype of endometriosis (77.2%). Out of the 14 patients with a desire for future pregnancy, the majority (11/14, 78.5%) had an EFI score of 7–8. The prevalence of bilateral ovarian dermoid cysts was higher in women with both ovarian dermoid cysts and endometriosis in comparison to women with ovarian dermoid cysts without endometriosis (18% vs. 6.5%). Our study revealed that 26.5% of women with ovarian dermoid cysts also had endometriosis, a notably higher prevalence than observed in the general population. Clinicians should be aware of this co-existence, and preoperative counseling should be an integral part of the care plan for affected individuals, where the potential risks and the available options for fertility preservation should be discussed in detail.