Ovarian cysts are fluid-filled sacs within the ovary. The most common types are functional follicular cysts, corpus luteum cysts, and theca lutein cysts, which all develop as part of the menstrual cycle and are usually harmless and resolve on their own. Nonfunctional cysts include chocolate cysts, which are related to endometriosis, dermoid cysts, cystadenomas, and malignant cysts (a type of ovarian cancer). All types can be diagnosed via pelvic ultrasound. While ovarian cysts are usually asymptomatic, complications due to rupture of a cyst can occur and may require treatment. Moreover, individuals with ovarian cysts are at increased risk of ovarian torsion, which requires surgical correction.
Ovarian cysts are fluid-filled sacs within the ovary.
Functional ovarian cysts
Functional cysts result from a disruption in the development of follicles or the corpus luteum and often resolve on their own.
- Follicular cyst of the ovary (most common ovarian mass in young women)
- Corpus luteum cyst
Theca lutein cysts
- Often multiple cysts that typically develop bilaterally
- Result from exaggerated stimulation of the theca interna cells of the ovarian follicles due to excessive amounts of circulating gonadotropins such as β-hCG
- Strongly associated with multiple gestations and
- Usually resolve once β-hCG levels have normalized
Nonfunctional ovarian cysts
A group of ovarian cysts that do not produce hormones.
- Usually asymptomatic unless complications occur
- Adnexal mass that is sometimes palpable
- Possibly signs of the underlying cause, such as:
- General findings
- Specific findings
- In most patients with functional cysts, watchful waiting is recommended, as cysts often regress spontaneously.
- NSAIDs in the case of painful cysts
- Surgery in the case of complications, large cysts, or persistent cysts that are painful
- Treatment of underlying conditions such as polycystic ovary syndrome, endometriosis, or ovarian cancer
- Rupture is caused by an increase in intracystic pressure.
- Most common type of ruptured cyst: corpus luteum cyst 
- Vigorous physical activity
- Vaginal intercourse
- Large cysts
- Reproductive age
- May be asymptomatic
- Sudden-onset unilateral lower abdominal pain 
- Possible nausea and vomiting 
- Minimal vaginal bleeding (spotting) may occur in some cases.
- In case of significant hemorrhage: hypovolemic shock 
- Urine or serum β-hCG: obtain in all patients to exclude intrauterine or ectopic pregnancy
- CBC: may show anemia
- Pre-operative labs: type and screen, coagulation panel
- Transabdominal/transvaginal pelvic ultrasound: imaging modality of choice
- CT pelvis with IV contrast: consider in nonpregnant patients if ultrasound findings are inconclusive
- Characteristic findings: pelvic hemoperitoneum 
Hemodynamically unstable patients: : emergency exploratory laparoscopy/laparotomy to obtain hemostasis
- Suturing or cauterization of the ruptured section or cystectomy
- Consider oophorectomy in intractable hemorrhage
Hemodynamically stable patients: conservative management with analgesics and observation (see acute pain management).
- Consider outpatient treatment in patients with a small hemoperitoneum and no evidence of ongoing hemorrhage on imaging
- Inpatient management is recommended in patients if there is evidence of significant blood loss and/or ongoing hemorrhage 
- All patients: consider blood transfusion as needed (see blood transfusion)
Acute management checklist for ruptured ovarian cyst
- Urgent OB/GYN consult
- IV fluids (see IV fluid therapy)
- Parenteral analgesics: opioid analgesics are preferred.
- Order CBC, β-hCG, type and screen, coagulation panel.
- Obtain consent for blood transfusion.
- Hemodynamically stable patients: monitor vitals, Hb, and size of hemoperitoneum on imaging
- Hemodynamically unstable patients: emergency exploratory surgery for hemostasis
- Partial or complete twisting of the ovary and the fallopian tube around their supporting ligaments
- Also known as adnexal torsion or tubo-ovarian torsion
- Ovarian enlargement is the most important risk factor; common causes include:
- Long ovarian ligaments and laxity of pelvic ligaments (e.g., suspensory ligament) may be predisposing factors, especially in adolescents. 
- Strenuous physical activity 
- Twisting of the ovary and the fallopian tube around the infundibulopelvic ligament and ovarian ligament → compression of the ovarian veins and lymphatics → ↓ venous and lymphatic outflow → edema of the fallopian tube and ovary
- Worsening edema of the fallopian tube → compression of the ovarian artery → ovarian ischemia and necrosis
- Friable necrotic ovarian tissue → hemorrhage
- Ovarian necrosis is uncommon because the ovaries receive dual blood supply from the ovarian and uterine arteries.
- Sudden-onset unilateral lower abdominal and/or pelvic pain
- Nausea and vomiting
- Adnexal mass may be palpable
- Urine or serum β-hCG: to rule out pregnancy
- Pre-operative labs: CBC, coagulation panel, type and screen
- Transabdominal/transvaginal pelvic ultrasound with Doppler: imaging modality of choice 
MRI abdomen and pelvis with contrast 
- Indication: inconclusive findings on ultrasound
- Supportive findings
- CT abdomen and pelvis with IV contrast: not routinely recommended 
Emergency exploratory laparoscopy: indicated in all patients with suspected ovarian torsion
- Premenopausal women: adnexal detorsion and preservation of ovarian function
- Postmenopausal women: salpingo-oophorectomy 
- Additional procedures: based on intraoperative findings
- Ovarian cystectomy or drainage: in patients with ovarian cysts
- Oophoropexy: utero-ovarian ligaments are plicated or the ovary is fixed to either the posterior abdominal or pelvic sidewall to decrease the risk of retorsion.
- Supportive care
- Postoperative follow-up
- Prognosis: Viability may be preserved in ∼ 90% of cases even if there is intraoperative evidence of ovarian ischemia. 
- Ruptured or bleeding ectopic pregnancy
- Ruptured ovarian cyst
- Acute appendicitis
- See differential diagnoses of acute abdomen.