What Are Adnexal Tumors?

Medically Reviewed by Melinda Ratini, MS, DO on June 23, 2021

Adnexal tumors are growths near the uterus. They're also known as adnexal masses. They usually form in the ovaries, which make eggs and hormones, or the fallopian tubes, which connect your uterus and ovaries. The tumors can form in the connective tissue around this part of your body. Many conditions can cause an adnexal tumor and they can happen at any age. 

Types of Adnexal Tumors

Adnexal masses are classified based on where they're located and if they're cancerous or not. There are many types of adnexal masses, including: 

Benign ovarian. These masses are not cancerous and usually don't cause symptoms. They can be functional cysts or tumors. Functional cysts are sacs that form on your ovary and hold an egg. The sac usually goes away after the egg is released. Sometimes the egg isn't released or the sac closes after the egg is released. If this happens the sac can fill with fluid.   

Functional cysts are usually harmless and go away without treatment within a few months. Occasionally, cysts can grow large and cause problems such as painful twisting in your ovary. If a cyst ruptures, it can cause severe pain and internal bleeding. 

Benign ovarian tumors usually grow slowly and rarely become malignant, or cancerous. A tumor is different from a cyst because it's a solid mass. A cyst is filled with fluid. Tumors are abnormal growths of cells that don't have any purpose. Ovarian tumors are classified based on where they started forming. The most common type starts in the cells that line the surface of the ovary. 

Malignant ovarian. These tumors are cancerous. Ovarian cancer is rare but very serious because it isn't usually diagnosed until it's already advanced. Malignant ovarian tumors are also classified based on where they originally started to grow. 

The most common type is called epithelial. It begins in the cells that line the ovary. Malignant tumors can also start in the egg cells or in the tissue that holds the ovary together. 

Benign nonovarian. Masses that are noncancerous and are located outside of the ovaries can include: 

  • Ectopic pregnancy. When a fertilized egg starts to grow outside of your uterus, usually in the fallopian tubes.
  • Endometrioma. Cysts that develop when tissue that normally forms the inside of your uterine wall grows in your ovaries. 
  • Hydrosalpinx. When the end of your fallopian tube is blocked and fills with fluid. 
  • Leiomyoma. Tumors that start in the middle of the wall of your uterus. 
  • Tubo-ovarian abscess. A pocket of pus that forms because of an infection in your ovary and fallopian tube.

Malignant nonovarian. These are cancerous masses that form outside of the ovaries. Endometrial carcinoma is a type of cancer that begins in the lining of the uterus. Fallopian tube carcinoma is a type of cancer that begins in your fallopian tubes.

Nongynecologic. There are also conditions that can cause adnexal masses that don't have anything to do with your ovaries, fallopian tubes, uterus, or connective tissues. These can include:

  • Appendicitis. When your appendix is inflamed. 
  • Pelvic kidney. When your kidney is in your pelvis instead of your abdomen. 
  • Cancer in your gastrointestinal tract. 
  • Bladder diverticulum. A pouch in the wall of your bladder. 
  • Nerve sheath tumor. An abnormal growth on the covering of one of the nerves that branch off the spinal cord. 

How Are Adnexal Tumors Diagnosed?

Your doctor will listen to your symptoms and your medical history. They will perform a pelvic exam. Many adnexal masses aren't apparent with a pelvic exam, so you may need to have blood tests or an ultrasound. An ultrasound uses sound waves to create a picture of the inside of your body that displays on a monitor.   

Your doctor may do other tests if they need more information to diagnose your mass. You may need to have a biopsy done to check for cancer. A biopsy is when your doctor takes a sample of the mass to have it examined in a lab.

How Are Adnexal Tumors Treated?

The treatment for an adnexal tumor will depend on several factors, including what's causing it and where it's located. Generally, there are three options for treating adnexal masses: 

Expectant management. If your adnexal mass is not cancerous and your doctor thinks it will go away on its own, you may not need any treatment or follow-up care. This may be the case if you have a small cyst that will probably go away. 

Continued surveillance. If your doctor doesn't think your adnexal mass is cancerous but isn't certain, they may want to come back to be checked again later. You may need to have a pelvic ultrasound or blood tests during follow-up visits. 

Surgery. You may need to have surgery to remove the mass or take a sample of it if your doctor thinks it's cancer or if it's causing you problems. 

Show Sources


American Family Physician: "Diagnosis and Management of Adnexal Masses."

Mayo Clinic: "Ovarian cysts."

University of Colorado Gynecologic Oncology: "Benign Ovarian Tumors," "Ovarian Cancers."

UpToDate: "Management of an adnexal mass."

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