Ovarian Cysts in Emergency Medicine Follow-up

Timing of outpatient care of ovarian cysts depends on the patient’s age and pregnancy status.

• In pregnant patients, most ovarian cysts resolve at 16-20 weeks’ gestation.

  • Patients with benign-appearing ovarian cysts that are unilocular and smaller than 5-6 cm in diameter require no further follow-up for the cyst during pregnancy and require only routine prenatal visits.
  • If the cyst is larger than 5-6 cm or is multicystic, the patient should undergo follow-up ultrasonography at 16 weeks' gestation to allow time for cyst resolution. Persistent complex masses may be further characterized by MRI, either during or after pregnancy, to search for distinctive features that would guide diagnosis.^[6]
  • Ovarian cysts that are strongly suggestive of malignancy or that are larger than 8-10 cm in diameter, are symptomatic, or are at an increased risk for torsion, cyst rupture, or obstruction of labor are more likely to require surgical intervention^[17] and necessitate more urgent follow-up with an obstetrician and, possibly, a multidisciplinary approach in a timely fashion. If surgery is required, it is most advantageous to perform it in the early second trimester, as the risk of spontaneous abortion during this period is lower than in the first trimester. Surgical intervention is better to avoid during the third trimester, if possible, to prevent inducing preterm delivery and to avoid technical issues in dealing with a larger uterus.
• In postpartum patients, the size and complexity of the ovarian cyst and the CA-125 level are used to determine management. Unilocular cysts smaller than 5 cm in diameter should be monitored with transvaginal ultrasonography and CA-125 studies at 6-month intervals. Complex ovarian cysts that are smaller than 5 cm in diameter in the presence of normal CA-125 levels (defined as < 35-65 U/mL) should be monitored in 4 weeks with repeat ultrasonography and CA-125 studies. Surgery may be indicated for complex ovarian tumors smaller than 5 cm in diameter when CA-125 levels are elevated (>35-65 U/mL) and for complex tumors larger than 5 cm in diameter.^[15]
• In nonpregnant premenopausal patients, various studies have examined cyst resolution with various time frames being used as indices for cyst resolution. Most of these studies showed cyst resolution by 2-3 months, dictating ultrasonography with or without gynecological follow-up in these patients.^[18]

Epidemiological studies from the 1970s-1990s reported inverse relationships between oral contraceptive pill (OCP) use and surgically confirmed functional ovarian cysts. Short-term treatment with OCPs was thus used for initial management of ovarian cysts. However, recent meta-analyses have shown that there is no difference between OCP use and placebo in terms of treatment outcomes in ovarian cysts and that these masses should be monitored expectantly for several menstrual cycles. If a cystic mass does not resolve after this time frame, it is unlikely to be a functional cyst, and further workup may be indicated.^[18]

• When a female patient presents with abdominal pain and signs or symptoms of an intraperitoneal process of unclear etiology, transfer is indicated if any of the following conditions are met:

  • Backup surgical, obstetric, or gynecologic support is not available to the ED.
  • Operative capacity is not available at the health care delivery site.
  • Imaging capacity is not available at the facility.
• Unstable patients should not be transferred unless the facility is truly unable to provide appropriate treatment or evaluation. The patient is the responsibility of the transferring physician until arrival at the next hospital.

• Ovarian cysts have a broad range of potential outcomes. In most cases, the cyst is benign and asymptomatic, requires no further management, and will resolve on its own. In other cases, ovarian cyst–related accidents, such as rupture and hemorrhage or torsion, occur.
• Ovarian torsion involves the rotation of the ovarian vascular pedicle, causing obstruction to venous and, eventually, arterial flow that can lead to infarction. Most torsion cases occur in premenopausal females of child-bearing age, but up to 17% of cases affect prepubertal and postmenopausal women. It is also strongly associated with ovarian stimulation and polycystic ovarian syndrome. Ovarian torsion is more common on the right side owing to the sigmoid colon restricting the mobility of the left ovary. Malignancy may be seen in up to 2% of cases of ovarian torsion. The most common ovarian mass associated with torsion is a dermoid cyst. CT scanning and ultrasonography can assist with diagnosis. Treatment consists of laparoscopic detorsion and adnexal preservation in premenopausal women and bilateral oophorectomy in postmenopausal women.
• Ovarian cyst rupture commonly occurs with corpus luteal cysts. They involve the right ovary in two thirds of cases and usually occur on days 20-26 of the woman’s menstrual cycle. Mittelschmerz is a form of physiological cyst rupture. In pregnant women, hemorrhagic corpus luteal cysts are usually seen in the first trimester, with most resolving by 12 weeks' gestation. Hemorrhage and shock may occur and may present late in the symptomatology.
• In ovarian cyst rupture, ultrasonography may demonstrate free fluid in the pouch of Douglas in 40% of cases. Cyst rupture and hemorrhage may be treated conservatively with observation if the patient is stable, with follow-up scanning in 6 weeks to confirm hemorrhage resolution. Laparoscopy is indicated in hemodynamic compromise, possibility of torsion, no relief of symptoms within 48 hours, or increasing hemoperitoneum or falling hemoglobin concentration.
• Malignancy is also among the differential diagnoses of ovarian cysts. While not an ED diagnosis, appropriate follow-up must be available to ensure resolution of cyst, or further evaluation must be undertaken.^[3]

• The prognosis of ovarian cysts varies depending on the patient’s age and pregnancy status. Overall, 70%-80% of follicular cysts resolve spontaneously. Malignancy is a common concern among patients with ovarian cysts. Pregnant patients with simple cysts smaller than 6 cm in diameter have a malignancy risk of less than 1%. Most of these cysts resolve by 16-20 weeks' gestation, with 96% of these masses resolving spontaneously.^[19] In postmenopausal patients with unilocular cysts, malignancy develops in 0.3% of cases. In complex multiloculated cysts, the risk of malignancy climbs to 36%. If cancer is diagnosed, regional or distant spread may be present in up to 70% of cases, and only 25% of new cases will be limited to stage I disease.^[15]
• Ovarian cysts larger than 4 cm in diameter have been shown to have a torsion rate of approximately 15%. Ovarian function may be preserved with laparoscopic detorsion in 90% of cases.
• The outcome of ovarian cyst rupture is evaluated based on associated symptoms and will dictate whether patient may be discharged or admitted for laparoscopy.

For patient education resources, visit the eMedicine Women's Health Center and Cancer and Tumors Center; also, see the patient education articles Ovarian Cysts and Ovarian Cancer.