Approximately 20% of women will develop a pelvic mass at some time in their lives.1 Pelvic masses present gynecologists with difficulties in both diagnosis and management. When a patient presents with a pelvic mass, the gynecologist needs to first determine if the mass is gynecologic in origin and then determine whether it is benign or malignant. This article aims to aid physicians in the workup of pelvic masses and triage of patients with pelvic masses to the appropriate surgeon for optimal care.
Perhaps the most difficult challenge for reducing ovarian cancer mortality is the lack of effective screening. Patients with a personal lifetime risk of ovarian cancer of greater than 20% to 25% should undergo genetic testing. Women with a personal lifetime risk of 5% to 10% should be offered genetic testing.2 Women with BRCA mutations can be offered prophylactic measures to prevent ovarian cancer.
Aside from genetic testing, no standard screening method has been shown to decrease mortality rates from ovarian cancer. The screening program with the most data is the use of only serial CA-125 measurements at regular intervals to calculate a Risk of Ovarian Cancer Algorithm (ROCA) score, thereby determining whether a patient is at increased risk of ovarian cancer.3 An elevated ROCA score triages patients to transvaginal ultrasonography (TVS) for a determination about whether further management is necessary. In a recent study, more than 4000 women at average risk of ovarian cancer had a baseline CA-125 level determined and ROCA score calculated.4 If the score indicated low risk, patients were triaged to repeat CA-125 measurement in 1 year. Intermediate-risk women had CA-125 measurement repeated in 3 months and those at high risk underwent TVS and were referred to a gynecologic oncologist. The outcomes of this study demonstrate that the ROCA algorithm had a sensitivity of 40% and a specificity of 99.9% for detecting invasive ovarian cancer.4
The Prostate, Lung, Colorectal, and Ovarian Trial used CA-125 and TVS to predict risk of ovarian cancer. Of the 22,955 women in the intervention group, 1771 (7.7%) underwent oophorectomy because of abnormal screening findings. Of the 22,542 women in the usual care group, 1304 (5.8%) underwent oophorectomy because of abnormal screening findings. Of the women with abnormal findings on screening, only 1% had invasive ovarian cancer, and screening with CA-125 and TVS did not reduce mortality.5 Clearly, an ovarian cancer screening tool is very much needed that can be used to assess risk in the general population.
Differential diagnosis of pelvic masses
Because no universal screening for ovarian cancer currently exists, most gynecologists are faced with the challenge of determining the nature of a pelvic mass discovered on exam or imaging. The initial workup of a pelvic mass in a woman of reproductive age should include a pregnancy test. Once pregnancy is ruled out, the site of origin of the mass should be determined. Pelvic masses of nongynecologic origin include masses of the gastrointestinal and urinary tract. Patients with nongynecologic masses should be referred to the appropriate consultant.
For gynecologic pelvic masses, the uterus, fallopian tubes, and ovaries should all be considered possible sites of origin. Management of the majority of pelvic masses is relatively straightforward, whereas management of adnexal masses tends to be more difficult.
For women with adnexal masses, optimal care requires differentiating benign from malignant conditions. Although metastatic disease from other primary sites needs to also be ruled out, this review will focus on primary ovarian malignancies. One woman in every 72 in the United States will develop ovarian cancer during her lifetime.6 In the United States, a woman has a 5% to 10% lifetime risk of undergoing surgery for suspected ovarian cancer, and among those who undergo such surgery, the likelihood of being diagnosed with ovarian cancer is 13% to 21%.7