Adnexal masses can range from etiologies that are routinely normal to those that are pathologically malignant.
They can vary from asymptomatic to life-altering symptoms that occur continuously daily. In today’s article, we will be discussing the diagnosis and management of adnexal masses in female patients.
The Differential Diagnosis
The etiology of adnexal masses in females can be quite broad and can range from ovarian cysts to ovarian cancer and many other possibilities. A healthcare provider must be able to distinguish symptoms from various organ systems and be able to use multiple tests and imaging modalities to evaluate the chief complaint and determine if the etiology is benign or malignant punctually.
Ovarian cancer is found approximately around 22,000 times annually in the United States. This makes ovarian cancer the second most common gynecologic cancer, and in 2010 around 14,000 women died of ovarian cancer.
Screening for ovarian cancer has not been found to be effective in the general population with average risk factors. Unfortunately, due to there being no effective form of screening for ovarian cancer around 70 percent of cases are diagnosed in late stages.
However, if ovarian cancer is found at a stage in which the disease is limited to the ovary the survival rate is around 90 percent at 5 years.
The differential diagnosis of an adnexal mass can be quite daunting. Benign causes include but are not limited to:
- Luteal ovarian cysts
- Ectopic pregnancy
- Polycystic ovaries
- Tubo-ovarian abscesses.
- Malignant etiologies of an adnexal masses may be an endothelial carcinoma, sarcoma, or borderline tumors.1
Due to the fact that adnexal masses can have urinary, gastrointestinal, or metastatic origins, an ovarian source should not be presumed.
Abscesses, malignancy, and cysts of the GI tract or other abdominopelvic organs can appear as adnexal masses on an examination or on diagnostic imaging.
The History and Physical Exam
The history and examination are crucial in the diagnosis of an adnexal mass. It has been found that as a patient’s age increases as does their risk of ovarian cancer. A patient’s reproductive status, as well as their contraception choice, must be evaluated as an ectopic pregnancy can be a potential etiology.
Patients who have a family history of ovarian and breast cancer, are of Ashkenazi Jewish descent, or have a known family history of BRCA2 mutation are at an increased risk of ovarian cancer.
Other risk factors for ovarian cancer include obesity, delayed childbearing, nulliparity, unopposed estrogen exposure, and use of fertility-enhancing drugs.
Symptoms that may be present related to an adnexal mass may include bloating, irregular vaginal bleeding, dyspareunia, abdominal size increase, pelvic pain, urinary symptoms, and abdominal pain.
Abdominal or pelvic pain, urinary symptoms, and increased abdominal size, as well as those symptoms that are more severe and frequent for a shorter period of time, can be more indicative of malignancy rather than a benign etiology, and should not be ignored.
The Workup for the Adnexal Mass
Laboratory testing should be based upon symptoms that a patient presents with. In all patients who are pre- or perimenopausal, a pregnancy test must be completed. This test will aid in the evaluation of an ectopic pregnancy. Normally serial quantitative beta-hCG should increase by more than 50 percent in two days.
An intrauterine pregnancy is likely when with beta-hCG is greater than 1,500 to 2,000 mIU per mL. Heterotopic pregnancy (when there is both an intrauterine pregnancy and extrauterine pregnancy simultaneously) exists in around 1 per 30,000 pregnancies from spontaneous pregnancies, whereas it can increase to around one percent of pregnancies in those who have assistive reproductive methods completed.
A CBC may aid in the differentiation of an adnexal mass, where an elevated WBC count may be more indicative of PID, pelvic abscess, tubo-ovarian abscess or colonic origin.
A CA-125 should not be completed as a screening tool; however, this lab test can assist in the evaluation of an adnexal mass. CA-125 levels may be elevated in a myriad of diagnoses other than ovarian cancer, as seen below.
Managing the Mass
Next, we will discuss the management of an adnexal mass in female patients based upon three categories, if a patient is: premenarchal, pregnant, or non-pregnant.
A retrospective study revealed that in around 25 percent of patients with adnexal masses that were younger than 18 years of age were malignant. Therefore, an adnexal mass that is found in a premenarchal female, or if a premenarchal patient has symptoms of an adnexal mass, prompt referral to gynecology should be made.
Next, for those patients who are pregnant. The initial concern in this subset of patients is an ectopic pregnancy when an adnexal mass is identified. If an ectopic pregnancy is found, this should be managed with appropriate pharmacologic or surgical management by OB/GYN.
Antepartum ultrasound will often reveal ovarian cysts in women with an intrauterine pregnancy. The incidence of ovarian cysts in these cases range from 2.3 to 5 percent, and 76 percent of these cysts are 5 cm or smaller. Less than one percent of adnexal masses found during pregnancy are malignant.
Concerning features for malignancy on ultrasound include large size, projections, complexity, irregularities, septations or bilateral findings. If an ultrasound is inconclusive, then an MRI should next be completed.
Most adnexal masses found in pregnancy will often resolve on their own with time. Observation of these masses during pregnancy has shown no adverse outcomes on the neonate. Therefore, only rapidly growing or extremely suspicious masses should undergo intrapartum surgery.
Observation does pose the increased risk of ovarian torsion, however. CA-125 levels will tend to be elevated in pregnancy; however, if this level is markedly raised, it may be indicative of ovarian malignancy.
In those patients who are not pregnant, a high level of suspicion should be maintained in those who have new or progressive abdominal or pelvic complaints. Because the sensitivity of pelvic examinations is low further workup with transvaginal ultrasound is the initial choice for imaging.
If there is the concern of disease that has extended outward from the ovary, a CT scan of the abdomen and pelvis should be completed.
CA-125 levels should not be the sole factor in determining if a mass is malignant or benign. In the majority of benign cases the CA-125 level is less than 20 U/mL; however, levels up to 45 U/mL can be normal in patients with endometriomas and abscesses.
Endometriomas tend to be more likely in those patients who are premenopausal, whereas ovarian cancer is more common to present in postmenopausal patients (three times more likely).
In patients who are postmenopausal if a CA-125 level is found to be greater than 35 U/mL, diagnostic transvaginal ultrasound is indicated.
The Risk of Malignancy Index (RMI) uses menopausal status, CA-125 levels, and ultrasound findings to predict the chance that an adnexal mass is malignant.
The commonly used RMI score of 200 or higher as being concerning for malignancy has been questioned, however. This is due to the fact that patients of different race or ethnicities may have a different cutoff range to predict ovarian malignancy.
Studies have shown that in Asian populations a cutoff of 250 showed greater predictability of malignancy than the cutoff of 200 used in other populations.
In those postmenopausal patients who have a pelvic mass, elevated CA-125 level, evidence of metastasis, or presence of ascites should warrant an urgent referral to gynecologic oncology. The same goes for premenopausal patients who have highly elevated CA-125 levels, evidence of metastasis, or ascites present.
Lastly, even though data is unfounded currently, ultrasonography should be used to monitor adnexal lesions that are suspected of being benign. There are no current consensus guidelines for how often or how long to monitor these lesions for; however, MD Anderson does have recommended guidelines for monitoring ovarian cysts which you can find here: https://www.mdanderson.org/content/dam/mdanderson/documents/for-physicians/algorithms/clinical-management/Clin%20Management%20Ovarian%20Cysts%20WEB%20Algorithm.pdf
1. Am Fam Physician. Diagnosis and Management of Adnexal Masses. 2016;93(8):676-681. Copyright © 2016 American Academy of Family Physicians.
2. MD Anderson. Ovarian Cyst – Incidental Finding. Accessed: March 25, 2019.
3. UpToDate. Approach to the Patient with an Adnexal Mass. Accessed: March 25, 2019.