Design: Retrospective cohort study

Setting: Tertiary academic medical center

Patients or Participants: 104 patients with AE only and 105 patients with concurrent AE and a gynecologic malignancy.

Interventions: We collected data from all patients diagnosed with AE on surgical pathology, (January 2001 to September 2021) divided into cohorts based on the status of concurrent gynecologic malignancy at the time of surgery. For patients with AE alone, data was collected on demographics, location, surgery, follow-up, and development of gynecologic malignancy. For patients with concurrent malignancy, data was also collected on malignancy and malignancy location. Descriptive statistics and comparative analyses (Wilcoxon rank sum, Pearson’s chi-squared, and Fisher’s exact test) were performed.

Measurements and Main Results: There was a total of 436.6 person-years of follow-up for the AE alone cohort, with one case of ovarian malignancy. Of those with concurrent malignancy, the most common type was endometrioid or borderline endometrioid ovarian cancer (n = 48, 46%); this remained true among the 90 patients (86%) that had collocated malignancy and AE (n = 48, 53%). The most common location of AE was the left ovary in both groups (60% and 63%). Patients with AE alone were more likely to be younger (42 vs 56 years, p <0.003), have lower body mass index (29 vs 32, p <0.001), and be parous (66% vs 48%, p <0.010).

Conclusion: The ovaries were the most common location of AE in our sample; among those with both concurrent and collocated AE and ovarian malignancy, the most common type was endometrioid or borderline endometrioid. For those who have had excision of AE, malignant transformation is uncommon.