The cause of ORS is the unintentional retention of ovarian tissue after the procedure to remove the ovaries. If a woman is receiving hormone replacement therapy, distinguishing from other disease process may be difficult. Other confounding conditions contributing to ORS are thick and profuse pelvic adhesions, inflammation, bleeding after surgery (peri-operative bleeding), and ovaries which are retroperitoneal, can all contribute to the unintentional preservation of ovarian fragments. Risks The risk of ovarian<unk>  (ORS) is increased by incomplete removal of the ovary 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: * 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 Ovarian<unk>  (ORS) may first be considered in women who have undergone oophorectomy and have suggestive symptoms, the presence of a 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 should be performed to evaluate for a pelvic mass.1
Ovarian remnant syndrome
Heterotopic pregnancy
Ovarian vein syndrome
Persistent Müllerian duct syndrome
Ovarian hyperstimulation syndrome
Mixed Müllerian tumor
Persistent adrenarche syndrome
Ovarian torsion