Ovarian remnant syndrome

The most common symptom of ovarian remnant syndrome (ORS) is pelvic pain. Less common symptoms include a pelvic mass and/or the absence of menopausal symptoms after oophorectomy. Some people have symptoms consistent with endometriosis, including difficult or painful intercourse; urinary symptoms; or bowel symptoms. It is likely that some people with ORS don't have any symptoms, but the rate of this is unknown.^[1]

In most cases, symptoms occur within the first five years of the oophorectomy, although there are reports of ORS presenting 20 years after the initial surgery.^[1]

The risk of ovarian remnant syndrome (ORS) is increased by incomplete removal of the ovarian tissue at the time of oophorectomy. Surgical factors that contribute to incomplete removal include those that limit surgical exposure of the ovary, or compromise surgical technique. Factors may include:

• Pelvic adhesions – these can limit visualization of the ovary and may also cause it to adhere to surrounding tissues. Adhesions are often present due to preexisting conditions and/or prior surgeries. In the majority of cases reported since 2007, endometriosis was the most common indication for the initial oophorectomy in patients who subsequently had ORS. Endometriosis increases the risk for functional ovarian tissue being embedded into adjacent structures, making complete excision of tissue challenging.
• Anatomic variations - unusual location of ovarian tissue, for example
• Intraoperative bleeding
• Poor surgical technique – this may include failure to obtain adequate exposure or restore adequate anatomy, or imprecise choice of incision site^[1]

Ovarian remnant syndrome (ORS) may first be considered in women who have undergone oophorectomy and have suggestive symptoms, the presence of a pelvic mass, or evidence of persistent ovarian function (by symptoms or laboratory testing). A history of oophorectomy is required, by definition, to make the diagnosis. Notes regarding the indication for the procedure and the procedure itself should be reviewed and may include prior abdominal or pelvic surgery, endometriosis, and/or poor surgical visualization. If ORS is possible, pelvic ultrasound should be performed to evaluate for a pelvic mass.^[1]

Surgical exploration and biopsy of possible ovarian tissue is required for the definitive diagnosis of ORS, and treatment by excision of the remnant ovarian tissue may be performed during the same procedure. For women who are not candidates for surgery, a clinical diagnosis can be made based on the symptoms and hormone levels (follicle-stimulating hormone and estradiol, after bilateral oophorectomy) and/or imaging findings consistent with the presence of residual ovarian tissue.^[1]

Treatment for ovarian remnant syndrome (ORS) is generally indicated for women with suspected ORS who have symptoms (such as pelvic pain); have a pelvic mass; or need or desire complete removal of tissue to decrease the risk of ovarian cancer (for example, BRCA mutation carriers). The mainstay of treatment is surgery to remove the residual ovarian tissue. Women with ORS with a pelvic mass should have appropriate evaluation for malignancy (cancer). Hormonal therapy to suppress ovarian function is an alternative treatment for those who refuse surgery, or those who are not candidates for surgery.^[1]

The incidence of ovarian remnant syndrome is difficult to determine. The available data are limited to case reports or to retrospective case series. The best available data are from a study describing the frequency and outcome of laparoscopy in women with chronic pelvic pain and/or a pelvic mass who were found to have ovarian remnants.^[1] In 119 women who underwent hysterectomy and oophorectomy by laparoscopy, ovarian remnants were known in 5 and were found during surgery in 21 patients (18%).^[2] However, this was a small study and the participants were only symptomatic women.^[1] Therefore, it is not known whether the data can be extrapolated to include all women who have undergone oophorectomy.