Tehran University of Medical Sciences Journal of Family and Reproductive Health 1735-8949 3 2 2009 06 15 67 70 Marzieh Agha Hosseini Shariati Hospital (Department of Infertility), Tehran University of Medical Sciences, Tehran, Iran Ashraf Aleyasin Shariati Hospital (Department of Infertility), Tehran University of Medical Sciences, Tehran, Iran Sepideh Khodaverdi Shariati Hospital (Department of Infertility), Tehran University of Medical Sciences, Tehran, Iran Atossa Mahdavi Shariati Hospital (Department of Infertility), Tehran University of Medical Sciences, Tehran, Iran Zahra Najmi Shariati Hospital (Department of Infertility), Tehran University of Medical Sciences, Tehran, Iran 2015 10 04 Endometriosis is an estrogen dependent disease. Levels of Cancer antigen-125 are significantly higher in women with moderate to severe endometriosis. However, patients with unruptured endometriosis rarely have serum CA-125 levels more than 1000 U/mL. This case report presents a diffuse, unruptured ovarian endometrioma in a 29- year-old woman, leading to an extraordinary high serum CA-125 and CA19-9 levels; usually typical of advanced ovarian carcinoma. Our experience emphasizes on benign gynecologic conditions such as endometrioma, which should be taken into account as a possible differential diagnosis in women with exaggerated elevation of the serum CA-125 level. https://jfrh.tums.ac.ir/index.php/jfrh/article/view/69 https://jfrh.tums.ac.ir/index.php/jfrh/article/download/69/69