**Abstract**

Endometriosis is a chronic debilitating inflammatory disease of women, with the growth of ectopic endometrium in extrauterine sites like rectovaginal septum, peritoneal surfaces, or ovaries, etc. Though endometriosis is not regarded as a malignant disorder, it does have some features common to malignant disease. They are; local and distant metastasis, invasion and destruction to adjacent structures, unrestricted growth, development of new blood vessels. The association between endometriosis and ovarian, endometrial, and cervical cancers and between endometriosis and extra-ovarian malignancies has been reported in different kinds of literature. Clear cell and endometrioid ovarian carcinomas are presumed to have developed from endometriosis. Ovarian seromucinous borderline tumors, low-grade serous ovarian carcinomas, adenosarcoma, and endometrial stromal sarcomas may also arise from endometriosis. However, it is not very clear whether endometriosis has undergone malignant transformation or simply is found co-existent with cancer. Endometriosis itself may increase a woman's risk of developing non-Hodgkin's lymphoma, malignant melanoma, and breast cancer.

**Keywords:** endometriosis, common genetic instability, cancer
