Although many ovarian masses are discovered incidentally, patients should be asked about any potential symptoms that might be associated with ovarian malignancy, such as persistent abdominal bloating, anorexia, early satiety, pelvic or abdominal pain, or increased urinary urgency and frequency. Clinicians should also assess the patient’s underlying risk by obtaining a thorough family history, especially regarding diagnoses of breast, uterine, colon, or ovarian cancers.
Although the physical examination is relatively insensitive for the diagnoses of ovarian masses, it is important to examine for any associated findings, such as lymphadenopathy. Palpable pelvic masses that are irregular, solid, fixed, nodular, or associated with ascites are particularly concerning for malignancy and should prompt urgent referral to a gynecologic oncologist.
B. Diagnostic Tests and Imaging
Transvaginal ultrasound is the diagnostic test of choice in any premenopausal or postmenopausal woman presenting with an ovarian mass. Ultrasonography should be performed by clinicians with expertise in gynecologic imaging who can provide a thorough description of the morphology and ultrasonographic features of the mass.
Ultrasound detection of a simple cyst is associated with a benign process in 95–99% of postmenopausal women. Simple cysts are characterized by a round or oval shape, a thin wall, posterior acoustic enhancement, anechoic fluid, and an absence of septations or nodules. Complex cysts may have solid components, septations, and papillary projections.
Ovarian masses may be characterized according to the International Ovarian Tumor Analysis (IOTA) “rules” (https://www.iotagroup.org/), which help differentiate benign from malignant ovarian mass processes (sensitivity 95%, specificity 91%). According to the IOTA classification, an ovarian mass is suspicious of being malignant when any of the following features are present: irregular solid tumor, irregular multilocular solid tumor with largest diameter greater than 1 cm, four or more papillary structures, ascites, and prominent blood flow on color Doppler. In 2020, the American College of Radiology developed the Ovarian-Adnexal Reporting and Data System (O-RADS), which applied the IOTA criteria to standardize the reporting of ovarian findings in ultrasound imaging reports and the process of communicating risk of malignancy to providers:
O-RADS ultrasound 0: adnexal lesions are incompletely characterized due to technical limitations; repeat imaging using ultrasound or MRI as needed.
O-RADS ultrasound 1: 0% risk of malignancy. Simple cysts less than or equal to 3 cm or corpus luteum less than or equal to 3 cm.
O-RADS ultrasound 2: Less than 1% risk of malignancy. Simple cysts greater than 3 cm but less than 10 cm; classic benign lesions less than10 cm (ie mature teratoma, hemorrhagic cysts, endometrioma); non-simple unilocular cyst less than 10 cm.
O-RADS ultrasound 3: 1–10% risk of malignancy. Mature teratoma/hemorrhagic cysts/endometriomas greater than or equal to 10 cm; unilocular cysts with irregular inner wall; multilocular cyst less than 10 cm with smooth inner wall, vascularity color score 1–3; solid smooth lesion of any size with color score of 1.
O-RADS ultrasound 4: 10–50% risk of malignancy. Unilocular cyst with solid component (0–3 papillary projections). Multilocular cysts: greater than 10 cm with smooth inner wall, color score 1–3; any size with smooth inner wall and color score 4; any size with irregular inner wall and/or septation, any color score; with solid component color score 1–2. Solid smooth lesions, any size, color score 2–3.
O-RADS ultrasound 5: greater than 50% risk of malignancy. Unilocular cyst with greater than or equal to 4 papillary projections and any color score. Multilocular cyst with solid component and color score 3–4. Solid smooth lesion, color score 4. Solid irregular lesion, any color score. Peritoneal findings such as ascites or nodules.
If an ovarian mass is suspected of being malignant, the patient should be urgently referred to a gynecologic oncologist.
Serum CA-125 is a biomarker that is expressed by most epithelial ovarian cancers. However, in premenopausal women, its serum level can also be elevated in benign conditions, such as endometriosis, pelvic inflammatory disease, and adenomyosis making it unreliable in the assessment of the risk of ovarian cancer (sensitivity 50–74%, specificity 26–92%). In contrast, in postmenopausal women, serum CA-125 does have utility in differentiating benign conditions from ovarian cancer. A CA-125 value above 35 units/mL is considered abnormal in postmenopausal women, though rising levels on serial determinations are more helpful than a single value.
Serum lactate dehydrogenase (LD), alpha-fetoprotein (AFP), and human chorionic gonadotropin (hCG) may be elevated in germ cell tumors, and these markers should be ordered in premenopausal women (under age 40 years) who have complex ovarian mass on ultrasound imaging.
Although measuring CA-125 can be useful in the evaluation of an ovarian mass, evidence does not support the use of serum CA-125 in routine screening for ovarian cancer in asymptomatic women.