An adnexal mass is a common gynecological presentation that can affect women of all ages. Typically, the mass is identified during an annual pelvic exam or incidentally when patients undergo pelvic imaging for evaluation of gastrointestinal or gynecological complaints.
The main goal of evaluating an adnexal mass in the nonacute setting is to rule out malignancy. A careful evaluation is needed to accurately distinguish benign from malignant masses, but often a definitive diagnosis only can be achieved with surgery. Hence, in the United States, women have a 5%-10% chance of undergoing surgery to evaluate a mass, but only 13%-21% of these patients are diagnosed with an ovarian cancer (Obstet. Gynecol. 2007;110:201-14).
We will review a stepwise approach for the evaluation of a newly diagnosed mass. As part of our review, we will discuss imaging findings that should prompt surgical evaluation or continued observation, as well as the correct use of the currently available serum biomarkers.
Dr. Daniel L. Clarke-Pearson
The majority of adnexal masses are benign and present most commonly in premenopausal women. However, in the outpatient setting, the evaluation approach should be aimed at ruling out malignancy regardless of age or reproductive status. The patient’s age should be considered clinically, as the suspicion for ovarian cancer should be heightened in postmenopausal women.
The evaluation should start with a detailed history because it may help in determining the etiology of the mass. Pelvic pain and pressure are very common but nonspecific symptoms in women with adnexal masses. However, if the pain is of sudden onset, urgent evaluation is warranted to rule out adnexal torsion or a ruptured hemorrhagic cyst. A history of dysmenorrhea and/or dyspareunia may suggest endometriosis and coexisting endometrioma, whereas a patient with fever and a vaginal discharge should be evaluated for a tubo-ovarian abscess.
Patients also should be asked about symptoms associated with ovarian cancer including early satiety, constipation, and bloating, as well as their duration. In addition, abnormal uterine bleeding or virilization may suggest the presence of estrogen- or testosterone-secreting tumors. Lastly, a detailed family history is important, as the presence of ovarian, breast, or colon cancer in the family would increase suspicion for hereditary ovarian cancer syndromes.
A thorough physical exam should include a speculum exam as well as bimanual and rectovaginal exams. The focus of the pelvic exam should be determining the size, mobility, and consistency of the mass, as well as other findings that may help discriminate benign versus malignant neoplasms. Malignant masses are usually solid, irregular in shape, and tend to be fixed. Nodularity in the posterior cul-de-sac also is associated with malignancy. The abdominal exam should focus on the presence or absence of ascites (fluid wave), an omental mass, or inguinal adenopathy. However, none of the findings on exam are specific for an ovarian or fallopian tube malignancy, and imaging should be obtained for further evaluation.
Ultrasound is the imaging study of choice for the evaluation of an adnexal mass because it is less expensive than and diagnostically equivalent to other imaging modalities. A pelvic ultrasound can help delineate the anatomic origin of the mass, but it also can detect characteristics of the mass that may help with the diagnosis, and the decision of whether or not to proceed to surgery. Endometriomas, mature teratomas (dermoid cysts), simple ovarian cysts, and hemorrhagic cysts have sonographic features that are highly predictive of the histology. Depending on whether or not the patient is symptomatic, the patient’s age, and comorbidities, these masses might be followed expectantly.
Ultrasound features that are suggestive of malignancy include solid components, septations greater than 2-3 mm, and vascular flow. The presence of ascites or peritoneal nodules detected at the time of ultrasound also is highly suspicious of malignancy in patients with a pelvic mass. If a pelvic ultrasound is equivocal, pelvic magnetic resonance imaging (MRI) is the second study of choice. Computed tomography (CT scan) should be used to evaluate for metastatic disease in patients with suspected ovarian carcinoma (ascites, adenopathy, peritoneal thickening or nodularity, omental thickening).
Dr. Dario R. Roque
Serum biomarkers also may aid in the evaluation. The most well-studied and commonly used biomarker in the evaluation of an adnexal mass is CA-125. In general, the utility of CA-125 is limited mainly because of its low specificity, especially in premenopausal women. However, it can be used as adjunct when an ovarian malignancy is suspected based on the patient’s history, risk factors, and imaging findings. The American College of Obstetricians and Gynecologists (ACOG) and the Society of Gynecologic Oncologists (SGO) advise referral to a gynecologic oncologist for postmenopausal women with an elevated CA-125. Meanwhile, for premenopausal women, the recommendation is for referral of those with a "very elevated" CA-125. However, a specific value has not been established (Obstet. Gynecol. 2011;117:742-6).