Malignant Transformation of Pelvic Endometriosis: Case Series and Review of the Literature.

Endometriosis affects 4% to 13% of all women of reproductive age although its true incidence is unknown. The ability of endometriosis to transform into malignancy, first described by Sampson in 1925, is a rare occurrence affecting 1% of lesions with ovary being the primary site in 79%. The authors describe 3 premenopausal women without risk factors for malignancy presenting with ovarian and/or extraovarian endometrioid adenocarcinoma. All of them demonstrated features of pre-/coexisting endometriosis but malignancy was preoperatively suspected in only 1 instance. Postsurgical follow-up of the cases did not document any recurrence. The propensity for malignant conversion occurring in women 10 to 20 years younger vis-a-vis those affected by de novo ovarian cancer, destruction of the endometriotic foci, and underreporting vindicate close follow-up and scrutiny of women with endometriosis and ovarian endometriomas.