Enhanced follicular recruitment and atresia in cortex derived from ovaries with endometriomas

ObjectiveTo evaluate the effects of endometriomas on the regulation of early follicular development.DesignHistologic analysis of prospectively collected biopsy samples.SettingResearch unit in a university hospital.Patient(s)Women <40 years of age who have ovarian endometriomas.Intervention(s)Biopsy of healthy cortex from ovaries affected by endometriomas (≤4 cm) and contralateral ovaries without cysts.Main Outcome Measure(s)Histomorphological staging of early follicles, measurement of follicle, oocyte, and oocyte nucleus diameters, immunohistochemistry of proliferating cell nuclear antigen, and caspase-3.Result(s)Thirteen cortical samples from ovaries with endometriomas and 13 samples from contralateral ovaries without endometriomas were evaluated. Cortex from ovaries with endometriomas contained significantly more morphologically atretic early follicles than cortex from contralateral ovaries without cysts. These follicles showed cleaved caspase-3 immunostaining. Diameters of primordial follicles and oocytes were decreased in cortex from ovaries with endometriomas, whereas early follicles with proliferating cell nuclear antigen-positive granulosa cells (GCs) were significantly increased in number.Conclusion(s)Ovaries with endometriomas, which may be more prone to local pelvic inflammation, showed activated follicular recruitment and atresia of early follicles. The potential contribution of inflammation to follicle “burnout” in case of endometriomas is discussed.