Benign Adnexal Masses

Types of adnexal masses that occur in reproductive-age and postmenopausal women are mostly the same. However, certain masses are stimulated by estrogen. Some estrogen-sensitive masses occur only during reproductive age, because they develop and resolve with the menstrual cycle (eg, follicular ovarian cysts, corpus luteum cysts). Other estrogen-sensitive masses begin to develop during reproductive age and typically decrease in size or resolve after menopause (eg, ovarian endometriomas).

Ovarian masses include:

• Benign, non-neoplastic masses: functional ovarian cysts (follicular or corpus luteum cysts), endometriomas, polycystic ovaries, theca lutein cysts (usually due to ovulation induction during infertility treatment)

• Benign neoplasms: fibromas, cystadenomas, benign cystic teratomas

• Paraovarian cysts

• Ovarian tumors of low-malignant potential (borderline tumors)

• Ovarian, fallopian tube, or peritoneal cancers

Fallopian tube masses include:

• Ectopic pregnanciesimplant most commonly in the tubes, but can also implant in the cervix, cornua of the uterus, ovaries, abdomen, or uterine scar

• Hydrosalpinges

• Tubo-ovarian abscesses: involve the tube and ovary and sometimes other pelvic structures (eg, intestines, bladder)

• Paratubal cysts

• Ovarian, fallopian tube, or peritoneal cancer

Most functional cysts and benign neoplasms are asymptomatic, but some cause intermittent dull or sharp pelvic pain or, infrequently, deep dyspareunia.

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.

Rarely, ascites and pleural effusion accompany ovarian fibromas;this triad of findings is called Meigs syndrome.

• Transvaginal ultrasound

• Sometimes tests for tumor markers

Adnexal masses are usually detected incidentally during pelvic examination or pelvic imaging but may be suspected based on symptoms.

Transvaginal ultrasound is usually the first-line test to evaluate an adnexal mass. A pregnancy test is done to exclude ectopic pregnancy in patients with an adnexal mass and pelvic pain or abnormal uterine bleeding.

Adnexal masses can be difficult to evaluate fully with imaging alone. Simple ovarian cysts (thin, smooth walls; no solid components, septations, or internal blood flow on Doppler imaging) are almost always benign, regardless of size or the patient's menopausal status (1, 2).

Radiographic characteristics that suggest cancer include a cyst with any of the following characteristics: > 10cm; papillary or solid components (particularly those with a blood supply); irregularity; thick septations; surface excrescences; ascites; evidence of metastases.

Ultrasound can usually diagnose mature teratomas and endometriomas with a high degree of certainty; other adnexal masses may be indeterminate. If ultrasound findings are indeterminate, MRI is performed (3).

The International Ovarian neoplasm Analysis (IOTA) group developed the Simple Rules to preoperatively assess risk of cancer in women who have ovarian or other adnexal neoplasms that are thought to require surgery. Classification is based on the presence or absence of 10 ultrasound features and has a higher sensitivity and specificity than other classification scores. The IOTA Simple Rules also include a risk calculation tool (SRrisk), which can be used on mobile devices (4).

Adnexal masses can be difficult to evaluate fully with imaging alone. Serum markers are measured if ovarian cancer is suspected, but sensitivity and specificity are limited. Tumor markers are more effective for monitoring response to treatment in patients with known ovarian cancer. The most commonly measured serum marker is CA 125, especially in postmenopausal women, but its use in premenopausal women requires clinical judgment. CA 125 levels may be falsely elevated in women who have endometriosis, uterine fibroids, peritonitis, cholecystitis, pancreatitis, inflammatory bowel disease, or various cancers. Another tumor marker, human epididymis protein 4 (HE4), has also been used to distinguish benign from malignant ovarian masses. If nonepithelial histopathology is suspected, beta human chorionic gonadotropin, L-lactate dehydrogenase, alpha-fetoprotein, or inhibin may be measured. , or various cancers. Another tumor marker, human epididymis protein 4 (HE4), has also been used to distinguish benign from malignant ovarian masses. If nonepithelial histopathology is suspected, beta human chorionic gonadotropin, L-lactate dehydrogenase, alpha-fetoprotein, or inhibin may be measured.

• Monitoring with serial transvaginal ultrasound for selected cysts

• Sometimes surgery (cystectomy, oophorectomy, salpingectomy)

Many functional cysts < 5 cm resolve without treatment; serial ultrasound 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 imaging characteristics of cancer, expectant management with repeated ultrasound (eg, every 6 to 8 weeks) is appropriate.

Benign neoplasms require treatment. Masses with radiographic characteristics of cancer require exploratory laparoscopy or laparotomy and excision.

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

• Other types of cysts that cannot be surgically removed separately from the ovary

• In postmenopausal women, most cysts or masses, particularly if they are > 5 cm

If oophorectomy is performed, concomitant salpingectomy may also be performed. Indications for salpingectomy at the time of ovarian cystectomy depend on patient characteristics and the clinical context and may include the following:

• Fallopian tube mass or other pathology, if malignancy is suspected, tubo-ovarian abscess is present, or if hydrosalpinx is present in patients planning in vitro fertilization

• Ectopic pregnancy

• Opportunistic salpingectomy to decrease risk of ovarian, fallopian tube, and primary peritoneal cancer is offered to patients at average risk of these cancers who are undergoing pelvic surgery for benign indications

The following is a list of professional medical society or government clinical practice guidelines regarding this medical issue; this is not a comprehensive list:

• Andreotti RF, Timmerman D, Strachowski LM, et al: O-RADS US Risk Stratification and Management System: A Consensus Guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee. 2020

• American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Gynecology. Practice Bulletin No. 174: Evaluation and Management of Adnexal Masses. 2016 (reaffirmed 2025).

• Expert Panel on GYN and OB Imaging, Patel-Lippmann KK, Wasnik AP, et al. ACR Appropriateness Criteria® Clinically Suspected Adnexal Mass, No Acute Symptoms: 2023 Update.