What Is an Adnexal Mass?

An adnexal mass is an abnormal growth that develops near the uterus, most commonly arising from the ovaries, fallopian tubes, or connective tissues. The lump-like mass can be cystic (fluid-filled) or solid. While most adnexal masses will be benign (non-cancerous), they can sometimes be malignant (cancerous).

Adnexal masses may occur at any age, although they are more typically seen in women of reproductive age.

Causes of an Adnexal Mass

There are literally hundreds of reasons why an adnexal mass may develop. In premenopausal women, they are often associated with ovarian cysts, benign ovarian tumors, endometriosis, polycystic ovary syndrome (PCOS), ectopic (tubal) pregnancy, and ovarian cancer.

Since adnexal masses are relatively common, doctors have to consider a number of factors to determine the cause and classification of the growth. While cancer is only one of many possible causes, red flags are typically raised if:

The mass is solid instead of cystic.
The mass is irregular in shape or density.
The mass develops before menstruation begins.
The mass develops after menopause.
The mass is painful.
When the cyst is extremely large.

Diagnosis

If an adnexal mass is found during a physical exam, there are several imaging tests that can aid in the diagnosis, including:

Magnetic resonance imaging (MRI) scan
Positron emission tomography (PET) scan

A pregnancy test may also be performed to help diagnose tubal pregnancy. If ovarian cancer is suspected, a CA 125 test (which measures a protein, called cancer antigen 125, in the blood) may be ordered.

If the mass is cystic, the doctor may perform an aspiration to extract fluid with a needle and syringe.

However, many doctors will avoid this, especially if cancer is suspected, since the extracted fluid may contain malignant cells that can seed other tumors.

Management and Treatment

Based on the initial findings, the doctor may either take a watch-and-wait approach, regularly monitoring for any changes in the mass, or start immediate interventions. This may include the surgical removal of the mass followed by lab evaluations.

In the event of a tubal pregnancy, emergency treatment may be required to prevent a potentially life-threatening rupture, especially if the woman is symptomatic.

In most cases, however, an adnexal mass will not be a cause for alarm and may never present any health problems to the woman.

With that being said, doctors will pay particular attention to any masses or lesions that appear in or around the ovaries or in fallopian tubes. Studies have shown that growths in the fallopian tubes often serve as precursors to high-grade serous ovarian carcinomas (HGSOC) years later. HGSOC accounts for around 75 percent of all ovarian cancers

A Word From Verywell

If an adnexal mass is found and cancer is suspected, it is always best to get a second option from a gynecologic oncologist who will be more experienced in the diagnosis, staging, and of treatment of endometrial and ovarian cancers.

By and large, survival times for women under the care of a gynecologic oncologist will be greater than those treated by a general surgeon.

Even if the adnexal mass turns out to be benign, a gynecologic oncologist will be better able to determine when changes in the growth warrant more aggressive interventions.

Sources:

Chan, K; Sherman, A.; Zapp, D. "Influence of gynecologic oncologists on the survival of patients with endometrial cancer." J Clin Oncol. 2011; 29(7):832-8. DOI: 10.1200/JCO.2010.31.2124.

Dodge, J. "Management of a suspicious adnexal mass: a clinical practice guideline." Curr Oncology. 2012; 19(4):e244-57. DOI: 10.3747/co.19.980.

Labidi-Galy, S.; Papp, E.; Hallberg, D. et al. "High grade serous ovarian carcinomas originate in the fallopian tube." Nat Commun. 2017; 8: 1093. DOI: 10.1038/s41467-017-00962-1.

Suh-Burgmann, E. and Kinney, W. "Potential harms outweigh benefits of indefinite monitoring of stable adnexal masses." Amer J Obstetric Gynecol. 2015; 213(6):816.e1-4. DOI: 10.1016/j.ajog.2015.09.005.