Prevalence of endometriosis in malignant epithelial ovary tumours

Abstract Objective : To determine the prevalence of ovarian endometriosis in malignant epithelial ovarian tumours. Study design : A retrospective analysis of 160 malignant and 23 borderline ovarian tumours during the period 1995–2001. Results : Fourteen (7.7%) of the tumours contained endometriosis. This affected 22% of the endometrioid and 10.8% of the mixed adenocarcinomas. The mean age of the ovarian endometriosis patients was 43±13 range 26–70 years. The incidence in borderline tumours 13% (3/23) was higher than that in ovarian cancer 6.9% (11/160) ( P >0.05). Eight (57%) of cases were classified as atypical and six (43%) as typical endometriosis. Nine cases were FIGO (International Federation of Gynaecology and Obstetrics) stage I and 5 stage III. Conclusions : Both malignant and borderline ovarian tumours are associated with ovarian endometriosis. In addition, atypical endometriosis was found associated with endometrioid and mixed epithelial ovarian tumours.