Ovarian Cysts in Emergency Medicine 

An ovarian cyst is a fluid-filled sac in an ovary. They can develop from the neonatal period to postmenopause. Most ovarian cysts occur during infancy and adolescence, which are hormonally active periods of development. Most are functional in nature and resolve with minimal treatment. However, ovarian cysts can herald an underlying malignant process or, possibly, distract the emergency clinician from a more dangerous condition, such as ectopic pregnancy, ovarian torsion, or appendicitis. When ovarian cysts are large, persistent, or painful, surgery may be required, sometimes resulting in removal of the ovary. With the more frequent use of ultrasonography in recent years, the diagnosis of ovarian cysts has become more common.

A large ovarian cyst is shown in the images below.

Abdominal pain in the female can be one of the most difficult cases to diagnose correctly in the emergency department (ED). The spectrum of gynecological disease is broad, spanning all age ranges and representing various degrees of severity, from benign cysts that eventually resolve on their own to ruptured ectopic pregnancy that causes life-threatening hemorrhage.

When presented with this scenario, the goal of the emergency physician is to rule out acute causes of abdominal pain associated with high morbidity and mortality, such as appendicitis or ectopic pregnancy, to assess for the possibility of neoplasm or malignancy, and either to refer the patient to the appropriate consultant or to discharge them with a clear plan for follow-up with an obstetrician/gynecologist.

The median menstrual cycle lasts 28 days, beginning with the first day of menstrual bleeding and ending just before the subsequent menstrual period. The variable first half of this cycle is termed the follicular phase and is characterized by increasing follicle-stimulating hormone (FSH) production, leading to the selection of a dominant follicle that is primed for release from the ovary. In a normally functioning ovary, simultaneous estrogen production from the dominant follicle leads to a surge of leuteinizing hormone (LH), resulting in ovulation and release of the dominant follicle from the ovary and commencing the leuteinizing phase of ovulation.

After ovulation, the follicular remnants form a corpus luteum, which produces progesterone. This, in turn, supports the released ovum and inhibits FSH and LH production. As luteal degeneration occurs in the absence of pregnancy, the progesterone levels decline, while the FSH and LH levels begin to rise before the onset of the next menstrual period.

Different kinds of functional ovarian cysts can form during this cycle. In the follicular phase, follicular cysts may result from a lack of physiological release of the ovum due to excessive FSH stimulation or lack of the normal LH surge at mid cycle just before ovulation. Hormonal stimulation causes these cysts to continue to grow. Follicular cysts are typically larger than 2.5 cm in diameter and manifest as pelvic discomfort and heaviness. Granulosa cells that line the follicle may also persist, leading to excess estradiol production, which, in turn, leads to decreased frequency of menstruation and menorrhagia.^[1]

In the absence of pregnancy, the lifespan of the corpus luteum is 14 days. If the ovum is fertilized, the corpus luteum continues to secrete progesterone for 5-9 weeks until its eventual dissolution in 14 weeks time, when the cyst undergoes central hemorrhage. Failure of dissolution to occur may result in a corpus luteal cyst, which is arbitrarily defined as a corpus luteum that grows to 3 cm in diameter. The cyst can cause dull, unilateral pelvic pain and may be complicated by rupture, which causes acute pain and possibly massive blood loss.

Theca lutein cysts are caused by luteinization and hypertrophy of the theca interna cell layer in response to excessive stimulation of beta-human chorionic gonadotropin (bhCG). This type of cyst can occur in the setting of gestational trophoblastic disease, multiple gestation, or exogenous ovarian hyperstimulation. These cysts are associated with maternal androgen excess in up to 30% of cases but usually resolve spontaneously as the bhCG level falls. Theca lutein cysts are usually bilateral and result in massive ovarian enlargement, a condition termed hyperreactio luteinalis.^[2]

Frequency

United States

Ovarian cysts are extremely prevalent, affecting an estimated 7% of premenopausal and postmenopausal woman. Furthermore, up to 4% of women will be admitted to the hospital with a primary diagnosis of ovarian cysts^[3] ; 1%-4% of pregnant women are diagnosed with an adnexal mass, with ovarian cysts accounting for most.^[4] Ovarian cysts are the most common fetal and infant tumor, with a prevalence exceeding 30%.^[5]

Mortality/Morbidity

• Ovarian cysts can result in pain and other morbidity, including menorrhagia, an increased intermenstrual interval, dysmenorrhea, pelvic discomfort, and abdominal distention.
• Approximately 3% of theca lutein cysts are complicated by torsion or hemorrhage, and approximately 30% of these cysts can cause maternal androgen excess.^[2]
• Follicular cysts can cause excess estradiol production, leading to metrorrhagia and menorrhagia.
• Ovarian cysts, and more specifically corpus luteal cysts, can rupture, causing hemoperitoneum, hypotension, and peritonitis. This can be exacerbated in women with bleeding dyscrasias, such as those with von Willebrand disease and those receiving anticoagulation therapy.
• Ovarian torsion can complicate ovarian cysts and can result in ovarian infarction, necrosis, infertility, premature ovarian menopause, and preterm labor.^[6]

Race

No racial discrepancies regarding ovarian cysts are reported in the literature. This disease affects all racial groups.

Age

Ovarian cysts affect all age ranges of females, from those in utero to postmenopausal women. Even benign-appearing ovarian cysts in postmenopausal patients may require aggressive treatment owing to the increased risk of malignancy in this population.