Abstract: Endometriosis (EMs) refers to the appearance of endometrial tissue outside the uterine body, with the ovaries and uterine ligaments being the most common. Atypical endometriosis (aEM) refers to the abnormal shape of endometrial glands that are located in the ovary, and its histology appears to be "borderline" or "transitional", which is a precancerous lesion. aEM is closely related to the occurrence and development of endometriosis associated ovarian cancer (EAOC), but its severity has not been paid enough attention, which makes the disease easily missed in clinical diagnosis. The research progress of the mechanism of ovarian aEM malignant transformation is described here, hoping to improve the clinician′s understanding of ovarian aEM and bring some help to clinical work.

Key words: Endometriosis；, Endometrial hyperplasia；, Ovarian neoplasms；, Genes；, Therapy