REPRODUCTIVE ENDOCRINOLOGY: Edited by David L. OliveOvarian remnant syndrome: etiology, diagnosis, treatment and impact of endometriosisKho, Rosanne M.a; Abrao, Mauricio S.bAuthor Information aDepartment of Medical and Surgical Gynecology, Mayo Clinic in Arizona, Phoenix, Arizona, USA bDivision of Endometriosis, Sao Paulo University, Sao Paulo, Brazil Correspondence to Rosanne M. Kho, MD, Assistant Professor, Department of Medical and Surgical Gynecology, Mayo Clinic, 5777 E Mayo Blvd, Phoenix, AZ 85054, USA. Tel: +1 480 342 2668; fax: +1 480 342 2944; e-mail: firstname.lastname@example.org Current Opinion in Obstetrics and Gynecology: August 2012 - Volume 24 - Issue 4 - p 210-214 doi: 10.1097/GCO.0b013e3283558539 Buy Metrics Abstract Purpose of review Ovarian remnant syndrome (ORS), a rare condition in which remnant ovarian tissue presents as a pelvic mass and/or pain after previous oophorectomy, poses a diagnostic and treatment challenge. This study reviews the recent studies in the past 5 years on the subject. Recent findings Incomplete removal of ovarian tissue at the time of initial oophorectomy from inability to obtain adequate surgical margins or inappropriate extraction from the pelvic cavity during laparoscopy can cause ORS. Excision of ovarian remnant tissue is increasingly approached minimally invasively. Cases of malignant involvement of the remnant ovary have been reported. Endometriosis, recently suggested to increase the risk for ovarian cancer, predisposes to ORS and is associated with 50% of patients with ovarian carcinoma in ORS patients. Summary Surgical excision remains the treatment of choice in ORS as malignancy can be associated with the remnant tissue. In cases of endometriosis, complete excision of endometriosis and ovarian tissue at the time of initial surgery prevents recurrence of endometriosis, subsequent development of ORS and possible ovarian malignant transformation. © 2012 Lippincott Williams & Wilkins, Inc.