An adnexal mass is a growth that occurs in or near the uterus, ovaries, fallopian tubes, and the connecting tissues. They’re usually benign, but are sometimes cancerous.

Some of them are filled with fluid, and some are solid. Doctors tend to be more concerned if they’re solid. The majority of masses don’t require treatment and will disappear on their own within a few menstrual cycles. Adnexal masses can occur at any age.

There are often no symptoms present with an adnexal mass. They’re usually discovered during a routine pelvic exam. However, an adnexal mass can cause symptoms in a few cases. These symptoms can include:

  • pain in the pelvic region
  • irregular periods in women who are experiencing premenopause
  • bleeding at the site of the mass
  • difficulty with urination
  • frequent urination
  • constipation
  • gastrointestinal disorders

Whether or not symptoms are present often largely depends on the size of the mass. Since these symptoms can be present in many different conditions, it’s important that you seek advice from your doctor if you experience them. Your symptoms will require further investigation.

There are many hundreds of causes of adnexal masses. The most common causes are described below.

Ovarian cysts

Ovarian cysts are fluid-filled sacs that develop on the ovaries. They’re very common. In fact, many women will experience at least one in their lifetime. Ovarian cysts are usually painless and don’t produce symptoms.

Benign ovarian tumors

An ovarian tumor is an abnormal lump or growth of cells. They differ from cysts in that they’re solid masses rather than filled with fluid. When the cells inside the tumor aren’t cancerous, it’s a benign tumor. This means it won’t invade nearby tissues or spread to other parts of the body. Depending on size, they may or may not produce symptoms.

Ovarian cancer

Ovarian cancer is one of the most common forms of cancer in women. Abnormal cells in the ovary multiply and form a tumor. This tumor has the capacity to grow and spread to other areas of the body. Symptoms are usually present in ovarian cancer and can include:

  • fatigue
  • indigestion
  • heartburn
  • constipation
  • back pain
  • irregular periods
  • painful intercourse

Ectopic pregnancy

An ectopic pregnancy is when a fertilized egg doesn’t make it to the uterus and implants in a fallopian tube instead. Ectopic pregnancies are unable to grow to term. If the egg continues to grow in the fallopian tube, the tube will rupture and cause heavy bleeding. This will cause sudden and severe pain and internal bleeding. Untreated ectopic pregnancies can be fatal for the woman.

If the adnexal mass is small and you have no symptoms, then it may not require treatment at all. However, your doctor will likely want to monitor you with regular pelvic exams and ultrasounds.

Surgery will be needed if:

  • the mass begins to grow
  • you develop symptoms
  • a cyst develops solid elements

Once removed, the adnexal mass will be tested to determine whether or not the cells contained within it are cancerous. If they are, further treatment may be required to ensure all cancerous cells have been removed from your body.

Adnexal masses are usually diagnosed by a pelvic exam, ultrasound, or both. Often, in cases when the woman isn’t showing any symptoms, the growth is detected during routine exams.

Once diagnosed, your doctor will decide if your case is an emergency. Usually it’s not, and your doctor will have time to investigate what’s causing the mass and the best way to proceed.

Imaging and lab tests can be used to determine the underlying cause of the adnexal mass. Your doctor will also probably have you take a pregnancy test to rule out an ectopic pregnancy, since this will need immediate treatment.

Ideally, an adnexal mass would be discovered and treated before a woman gets pregnant to avoid complications. However, adnexal masses are sometimes discovered during a pregnancy when having routine ultrasounds or pelvic exams.

Since the majority of adnexal masses aren’t harmful and mostly resolve on their own, it’s usually considered appropriate to monitor the mass closely during pregnancy without treatment.

Surgery would only be considered if:

  • your doctor suspects that the adnexal mass is malignant
  • a complication occurs
  • the mass is so big that it’s likely to cause a problem with the pregnancy

About 10 percent of adnexal masses discovered in pregnancy are malignant, according to one 2007 clinical review. Even in these cases, the cancer is usually in its early stages. This means the outlook for the mother is good. If a malignancy is discovered in your pregnancy, your doctor will allow your pregnancy to progress for as long as is safely possible before intervening.

The majority of adnexal masses aren’t harmful. They won’t require treatment unless a woman is experiencing uncomfortable symptoms. Many adnexal masses will resolve themselves without any intervention.

In a very small number of cases, the cause of the adnexal mass will be ovarian cancer. If the cancer is found and treated before it’s spread outside of the ovary, the five-year survival rate for ovarian cancer is 92 percent, according to the American Cancer Society.