A paratubal cyst is an encapsulated, fluid-filled sac. They’re sometimes referred to as paraovarian cysts.

This type of cyst forms near an ovary or fallopian tube, and won’t adhere to any internal organ. These cysts often dissolve on their own, or go undiagnosed, so their rate of occurrence is unknown.

Small, paratubal cysts are most commonly seen in women between the ages of 30 and 40. Enlarged cysts are more common in girls and younger women.

Keep reading to learn more about how they present, what causes them, and how they’re treated.

Paratubal cysts are typically small in size, ranging from two to 20 millimeters in diameter. When they remain that size, they’re usually asymptomatic. Your doctor may discover it during a gynecological exam or unrelated surgical procedure.

Large, ruptured, or twisted paratubal cysts can cause pelvic or abdominal pain.

When fetuses form, they all contain an embryonic structure called the wolffian duct. This area of the embryo is where male sex organs are formed.

If a fetus begins to form female sex organs, the duct shrinks away. Sometimes, vestiges of the duct remain. Paratubal cysts may grow out of these remnants.

The cysts may also form from vestiges of the paramesonephrontic (Müllerian) duct. This is the embryonic structure where female sex organs grow.

There aren’t any known risk factors for paratubal cysts.

If you’re experiencing pelvic or abdominal pain, see your doctor. They’ll review your symptoms and medical history, then perform a physical exam to check for areas of tenderness.

They may also use one or more of these diagnostic tests:

  • Pelvic ultrasound or abdominal ultrasound. These medical imaging tests use ultrasonic frequency vibrations to transmit visual images of the pelvic region to a computer screen.
  • MRI. This test helps your doctor determine whether a cyst is malignant. It may also be used to follow a cyst’s growth.
  • Blood tests. If malignancy is suspected, your doctor may order blood tests, such as a complete blood count (CBC) and tumor marker test.
  • Laparoscopy. Paratubal cysts can look similar to ovarian cysts on ultrasound, so your doctor may also suggest this surgical test. A diagnostic laparoscopy requires a small incision in the abdomen. Your doctor will insert a tube, which has a tiny video camera attached to its tip, into the incision. This allows your doctor to see your entire pelvic region.

If the cyst is small and asymptomatic, your doctor may recommend a “wait and see” approach. They’ll have you come in for periodic check-ups to monitor for any changes.

If the cyst is larger than 10 centimeters, your doctor may recommend removal regardless of whether you’re experiencing symptoms. This procedure is called a cystectomy. Your doctor will use one of these methods:

  • Laparoscopy. This procedure requires a small abdominal incision. It may be done under a local anesthetic or general anesthesia. It generally requires less recuperation time than a laparotomy.
  • Laparotomy. This procedure is more invasive, requiring a large abdominal incision. It’s always done under general anesthesia

Your doctor will take the condition, size, and location of the cyst into consideration before recommending one procedure over the other.

If you haven’t reached menopause, your doctor may prioritize a removal method that will preserve your ovary or fallopian tube.

In some cases, paratubal cysts can lead to complications like:

  • Hemorrhage. If the cyst ruptures, it may cause internal bleeding.
  • Torsion. This refers to a twisting of the cyst on its pedicle, which is the stalk-like structure that holds it in place. This can cause extreme, debilitating pain, as well as nausea and vomiting. Most instances of ovarian torsion have been reported in young girls.
  • Fallopian tube rupture. If situated near a fallopian tube, a too-large or twisted cyst may cause the tube to rupture.

Although giant cysts are rare, they’re possible. These cysts can place pressure on your internal organs, including the:

  • uterus
  • kidney
  • bladder
  • bowel

This pressure may result in hydronephrosis. This refers to kidney swelling caused by excess urine buildup.

Large cysts may also cause uterine bleeding and painful intercourse.

Small paratubal cysts shouldn’t have an impact on your fertility. But large, ruptured, or twisted cysts may lead to complications if left untreated.

Immediate surgical removal helps ensure preservation of the ovary and fallopian tube. If the cyst isn’t removed promptly, it may result in removal of the ovary (oophorectomy), fallopian tube (salpingectomy), or both.

Paratubal cysts are usually unilateral, meaning they only occur on one side of the body. Ovulation and pregnancy is still possible even if the ovary or tube on the affected side is removed.

Paratubal cysts usually aren’t accompanied by symptoms, so they often go undiagnosed. They may dissolve on their own over time.

However, large cysts may cause pain or other complications. These cysts must be surgically removed, but this usually won’t have a lasting effect on your fertility.