Benign ovarian masses include functional cysts and tumors; most are asymptomatic.

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.

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 tumors are usually < 7 cm in diameter.
• Cystadenomas: These tumors are most commonly serous or mucinous.

Symptoms and Signs

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

• Transvaginal ultrasonography

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. If results are indeterminate, MRI or CT may help.

Masses with radiographic characteristics of cancer (eg, cystic and solid components, surface excrescences, multilocular appearance, irregular shape) require excision. Tumor markers may help in the diagnosis of specific tumors (see Gynecologic Tumors: Diagnosis). In women of reproductive age, simple, thin-walled cystic adnexal masses 5 to 8 cm (usually follicular) without characteristics of cancer do not require further evaluation unless they persist for > 3 menstrual cycles.

Treatment

• Removal of selected cysts

Most ovarian cysts < 8 cm resolve without treatment; serial ultrasonography is done to document resolution. If technically feasible, cyst removal from the ovary (ovarian cystectomy) via laparoscopy or laparotomy may be necessary for the following:

• Most cysts that are ≥ 10 cm and that persist for > 3 menstrual cycles
• Cystic teratomas < 10 cm
• Hemorrhagic corpus luteum cysts with peritonitis
• Fibromas and other solid tumors

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

Last full review/revision December 2008 by S. Gene McNeeley, MD

Content last modified February 2012