Ovarian cysts

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.

Definition

Ovarian cysts are fluid-filled sacs within the ovary.

Types

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)
  • Develops when a Graafian follicle does not rupture and release the egg (ovulation) but continues to grow
  • Eventually develops into a large cyst (∼ 7 cm) lined with granulosa cells
  • Associated with hyperestrogenism and endometrial hyperplasia
• Corpus luteum cyst
  • Enlargement and buildup of fluid in the corpus luteum after failed regression following the release of an ovum
  • Produces progesterone, which may delay menses
  • Associated with progesterone-only contraceptive pills and ovulation-inducing medication
  • Common during pregnancy
• 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 gestational trophoblastic disease and multiple gestations
  • Usually resolve once β-hCG levels have normalized

Nonfunctional ovarian cysts

A group of ovarian cysts that do not produce hormones.

• Chocolate cysts
• Dermoid cysts
• Cystadenoma (serous or mucinous)
• Malignant cysts (form of ovarian cancer): higher risk in postmenopausal women

Clinical features

• Usually asymptomatic unless complications occur
• Adnexal mass that is sometimes palpable
• Possibly signs of the underlying cause, such as:
  • Menorrhagia in endometriosis
  • Hirsutism, acne, and infertility in polycystic ovary syndrome

Ovarian cancer must be ruled out in premenarchal and postmenopausal patients with a palpable ovarian mass.

Diagnosis

Pelvic ultrasound

• General findings
  • Smooth lining on all sides
  • Single (e.g., follicular cyst of the ovary, corpus luteum cyst) or multiple (e.g., polycystic ovary syndrome, multilocular theca lutein cysts)
  • Hypoechoic to anechoic
  • Fluid level
• Specific findings
  • Corpus luteum cyst
    • Simple ovarian cyst with walls of variable thickness
    • ↑ Vascularity (ring-of-fire sign)
    • Small central lucency
    • Occasionally, intracystic hemorrhage
  • Theca lutein cysts
    • Multiple, bilateral cysts with thin walls,
    • Clear content
    • Occasionally, a solid component

Treatment

• 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

Complications

• Ovarian torsion
• Ruptured ovarian cyst

Etiology ^[1]

• Rupture is caused by an increase in intracystic pressure.
• Most common type of ruptured cyst: corpus luteum cyst ^[2]
• Risk factors
  • Vigorous physical activity
  • Vaginal intercourse
  • Large cysts
  • Reproductive age

Clinical features

• May be asymptomatic
• Sudden-onset unilateral lower abdominal pain ^[3]
• Possible nausea and vomiting ^[3]
• Minimal vaginal bleeding (spotting) may occur in some cases.
• In case of significant hemorrhage: hypovolemic shock ^[3]

Diagnostics ^[3]

Laboratory studies

• 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

Imaging

• Transabdominal/transvaginal pelvic ultrasound: imaging modality of choice
  • Characteristic findings ^[2][3]
    • Free fluid, most commonly in the pouch of Douglas (rectouterine pouch) ^[4]
    • An adnexal mass may be visualized if the cyst is large.
  • Disadvantage: cannot reliably distinguish between ruptured ovarian cyst or ruptured ectopic pregnancy in a pregnant patient. ^[5]
• CT pelvis with IV contrast: consider in nonpregnant patients if ultrasound findings are inconclusive
  • Characteristic findings: pelvic hemoperitoneum ^[5]

Free fluid in the pouch of Douglas in a pregnant patient should raise concern for ruptured ectopic pregnancy (see ''Treatment'' in ectopic pregnancy).

Treatment ^[3][6][7]

• 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 ^[3]
    • Monitor vital signs, hemoglobin, and hemoperitoneum size on ultrasound.
    • Consider laparoscopy if there is concern for ongoing hemorrhage.
• All patients: consider blood transfusion as needed (see blood transfusion)

Differential diagnoses

• Ruptured or bleeding ectopic pregnancy
• Ovarian torsion
• Acute appendicitis
• Diverticulitis
• See differential diagnoses of acute abdomen.

Acute management checklist for ruptured ovarian cyst

• Urgent OB/GYN consult
• NPO
• 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

Definition

• Partial or complete twisting of the ovary and the fallopian tube around their supporting ligaments
• Also known as adnexal torsion or tubo-ovarian torsion

Etiology

• Ovarian enlargement is the most important risk factor; common causes include:
  • Ovarian cysts, especially: ^[8]
    • Cysts > 5 cm
    • Dermoid cysts (teratoma)
  • Ovarian tumors
  • Ovarian hyperstimulation syndrome
  • Pregnancy: especially following assisted reproductive technology ^[9]
• Long ovarian ligaments and laxity of pelvic ligaments (e.g., suspensory ligament) may be predisposing factors, especially in adolescents. ^[10]
• Strenuous physical activity ^[11][12]

Pathophysiology

• 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.

Clinical features

• Sudden-onset unilateral lower abdominal and/or pelvic pain
• Nausea and vomiting
• Adnexal mass may be palpable

Diagnostics

Laboratory studies

• Urine or serum β-hCG: to rule out pregnancy
• Pre-operative labs: CBC, coagulation panel, type and screen

Imaging ^[4][8]

• Transabdominal/transvaginal pelvic ultrasound with Doppler: imaging modality of choice ^[13]
  • Indication: all patients with suspected ovarian torsion
  • Supportive findings
    • Enlarged, edematous ovary with decreased blood flow
    • Thickened fallopian tube
    • Twisted vascular pedicle
• MRI abdomen and pelvis with contrast ^[4]
  • Indication: inconclusive findings on ultrasound
  • Supportive findings
    • Enlarged ovary with thickening of the ipsilateral fallopian tube
    • Deviation of the uterus to the ipsilateral side
    • Decreased contrast enhancement of the affected ovary
    • Twisted vascular pedicle (whirlpool sign)
    • Ascites (usually minimal)
• CT abdomen and pelvis with IV contrast: not routinely recommended ^[4]
  • Indication: inconclusive ultrasound findings and MRI is not available
  • Contraindication: pregnancy
  • Findings: similar to MRI

Treatment

Surgery with adnexal detorsion and preservation of ovaries is the mainstay of treatment.

• Emergency exploratory laparoscopy: indicated in all patients with suspected ovarian torsion
  • Premenopausal women: adnexal detorsion and preservation of ovarian function
    • Intraoperative findings: enlarged purple or blue-black ovary, twisted fallopian tube
    • Oophorectomy should only be performed if the ovary is frankly necrotic or gangrenous. ^[10][14][15]
  • Postmenopausal women: salpingo-oophorectomy ^[10]
  • 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.
      • Indications ^[16]
        • Ovarian torsion in a patient with a single ovary
        • Bilateral ovarian torsion
        • Recurrent ovarian torsion
        • Patient with risk factors for retorsion (e.g., polycystic ovaries)
      • Oophoropexy of the contralateral ovary may be considered in high-risk patients.
• Supportive care
  • IV fluid resuscitation (see IV fluid therapy)
  • Analgesics (see acute pain management)
  • Antiemetics as needed
• Postoperative follow-up
  • Consider second-look laparoscopy if there is concern for ovarian gangrene. ^[10]
  • Pelvic ultrasound may be used to evaluate follicular development a few weeks/months after detorsion.
• Prognosis: Viability may be preserved in ∼ 90% of cases even if there is intraoperative evidence of ovarian ischemia. ^[10][15]

Diagnostic laparoscopy should be performed if there is strong clinical suspicion for ovarian torsion despite inconclusive imaging findings.

Differential diagnoses

• Ruptured or bleeding ectopic pregnancy
• Ruptured ovarian cyst
• Acute appendicitis
• Diverticulitis
• See differential diagnoses of acute abdomen.

Acute management checklist for ovarian torsion ^[15]

• Urgent OB/GYN consult
• NPO and IV fluids
• Parenteral analgesics: Opioid analgesics are preferred.
• Order CBC, β-hCG, type and screen, coagulation panel.
• Confirm diagnosis with imaging (pelvic ultrasound preferred)
• Transfer to OR for laparoscopy and immediate adnexal detorsion.