Ovarian endometrioid adenocarcinoma arising from endometriosis in a young woman

Background The risk of ovarian cancer increases in women with a long history of ovarian endometriosis, particularly in postmenopausal women. We present here a case of malignant transformation of endometriosis occurring over a short time in a young woman. Case The 27-year-old woman underwent laparoscopic cystectomy and was diagnosed with left ovarian endometrioma with an accompanying high level of serum CA125 (734.6 U/mL). Fourteen months later, she underwent cytoreductive surgery for her ovarian cancer. Histological examination revealed endometrioid adenocarcinoma with transitions between endometriosis and adenocarcinoma. She was diagnosed as having stage IIIc of ovarian cancer with paraaortic lymphnode involvement. Conclusion We suggest that endometrial cyst of the ovary associated with high levels of serum CA125 should be managed with special care even in a young woman.