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Benign Ovarian Masses


Charlie C. Kilpatrick

, MD, MEd, Baylor College of Medicine

Last full review/revision Mar 2021| Content last modified Mar 2021

Benign ovarian masses include functional cysts and tumors; most are asymptomatic. Treatment varies depending on the patient's reproductive status.

Functional cysts

There are 2 types of functional cysts:

  • Follicular cysts: These cysts develop from graafian follicles.
  • Corpus luteum cysts: These cysts develop from the corpus luteum. They may hemorrhage into the cyst cavity, distending the ovarian capsule or rupturing into the peritoneum.

Most functional cysts are < 1.5 cm in diameter; few exceed 5 cm. Functional cysts usually resolve spontaneously over days to weeks. Functional cysts are uncommon after menopause.

Polycystic ovary syndrome is usually defined as a clinical syndrome, not by the presence of ovarian cysts. But ovaries typically contain many 2- to 6-mm follicular cysts and sometimes contain larger cysts that contain atretic cells.

Benign tumors

Benign ovarian tumors usually grow slowly and rarely become malignant. They include the following:

  • Benign cystic teratomas: These tumors are also called dermoid cysts because although derived from all 3 germ cell layers, they consist mainly of ectodermal tissue.
  • Fibromas: These slow-growing connective tissue tumors are usually < 7 cm in diameter.
  • Cystadenomas: These tumors are most commonly serous or mucinous.

Symptoms and Signs of Benign Ovarian Masses

Most functional cysts and benign tumors are asymptomatic. Sometimes they cause menstrual abnormalities. Hemorrhagic corpus luteum cysts may cause pain or signs of peritonitis, particularly when they rupture. Occasionally, severe abdominal pain results from adnexal torsion of a cyst or mass, usually > 4 cm.

Ascites and rarely pleural effusion may accompany fibromas.

Diagnosis of Benign Ovarian Masses

  • Transvaginal ultrasonography
  • Rarely, tests for tumor markers

Masses are usually detected incidentally but may be suggested by symptoms and signs. A pregnancy test is done to exclude ectopic pregnancy. Transvaginal ultrasonography can usually confirm the diagnosis.

Masses with radiographic characteristics of cancer (eg, cystic and solid components, surface excrescences, multilocular appearance, irregular shape) require consultation with a specialist and excision.

Tests for tumor markers are done if a mass requires excision or if ovarian cancer is being considered. One commercially available product tests for 5 tumor markers (beta-2 microglobulin, cancer antigen [CA] 125 II, apolipoprotein A-1, prealbumin, transferrin) and may help determine the need for surgery. Tumor markers are best used for monitoring response to treatment rather than for screening, for which they lack adequate sensitivity, specificity, and predictive values. For example, tumor marker values may be falsely elevated in women who have endometriosis, uterine fibroids, peritonitis, cholecystitis, pancreatitis, inflammatory bowel disease, or various cancers.

Treatment of Benign Ovarian Masses

  • Observation of selected cysts
  • Sometimes surgery (cystectomy or oophorectomy)

Many functional cysts < 5 cm resolve without treatment; serial ultrasonography is done to document resolution. If asymptomatic women of reproductive age have simple, thin-walled cystic adnexal masses 5 to 8 cm (usually follicular) without characteristics of cancer, expectant management with repeated ultrasonography is appropriate. Benign tumors require treatment.

Masses with radiographic characteristics of cancer are excised laparoscopically or by laparotomy.

If technically feasible, surgeons aim to preserve the ovaries (eg, by cystectomy).

Oophorectomy is done for the following:

  • Fibromas that cannot be removed by cystectomy
  • Cystadenomas
  • Cystic teratomas > 10 cm
  • Cysts that cannot be surgically removed separately from the ovary
  • Most cysts that are detected in postmenopausal women and that are > 5 cm

Key Points

  • Functional cysts tend to be small (usually < 1.5 cm in diameter), to occur in premenopausal woman, and to resolve spontaneously.
  • Functional cysts and benign tumors are usually asymptomatic.
  • Exclude ectopic pregnancy by doing a pregnancy test.
  • Excise masses that have radiographic characteristics of cancer (eg, cystic and solid components, surface excrescences, multilocular appearance, irregular shape).
  • Excise certain cysts and benign tumors, including cysts that do not spontaneously resolve.

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