Park KJ, et al. - An exploratory analysis was conducted of the origin of ovarian cortical inclusion cysts (CICs) in women undergoing the risk-reducing salpingo-oophorectomy. Several positive for PAX8 (PAX8+) CICs possibly arose from metaplasia of ovarian surface epithelium (OSE)-derived CICs. This was illustrated via the yielded results and the increased ratio of PAX8+ to positive for calretinin (CALRETININ+) CICs from premenopausal to postmenopausal. The ratio of PAX+/CALRETININ- CICs arising from OSE-derived CICs was disclosed to be unclear. However, strong support was provided for the proposal that many Mullerian-CICs arose from OSE via metaplasia.