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 Polycystic Ovary Syndrome (PCOS) Polycystic ovary syndrome is a clinical syndrome typically characterized by anovulation or oligo-ovulation, signs of androgen excess (eg, hirsutism, acne), and multiple ovarian cysts in the... read more 
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 Adnexal Torsion Adnexal torsion is twisting of the ovary and sometimes the fallopian tube, interrupting the arterial supply and causing ischemia. Adnexal torsion is uncommon, occurring most often during reproductive... read more 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 Diagnosis Ovarian cancer is often fatal because it is usually advanced when diagnosed. The most common histology—high-grade serous epithelial ovarian cancer—is considered as a single clinical entity along... read more 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 Endometriosis In endometriosis, functioning endometrial cells are implanted in the pelvis outside the uterine cavity. Symptoms depend on location of the implants. The classic triad of symptoms is dysmenorrhea... read more , uterine fibroids Uterine Fibroids Uterine fibroids are benign uterine tumors of smooth muscle origin. Fibroids frequently cause abnormal uterine bleeding, pelvic pain and pressure, urinary and intestinal symptoms, and pregnancy... read more 
, peritonitis, cholecystitis Acute Cholecystitis Acute cholecystitis is inflammation of the gallbladder that develops over hours, usually because a gallstone obstructs the cystic duct. Symptoms include right upper quadrant pain and tenderness... read more , pancreatitis Acute Pancreatitis Acute pancreatitis is acute inflammation of the pancreas (and, sometimes, adjacent tissues). The most common triggers are gallstones and alcohol intake. The severity of acute pancreatitis is... read more 
, inflammatory bowel disease Overview of Inflammatory Bowel Disease Inflammatory bowel disease (IBD), which includes Crohn disease and ulcerative colitis, is a relapsing and remitting condition characterized by chronic inflammation at various sites in the gastrointestinal... read more , 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.
