Diaphragmatic endometriosis is a rare form of endometriosis in which tissue that resembles the uterine lining, called the endometrium, grows on the diaphragm. Symptoms can include stiffness, discomfort, chest pain, and more. It can also cause heavy, painful periods.

The diaphragm is a dome-shaped sheet of skeletal muscle that separates the abdomen from the chest and allows a person to breathe. When endometriosis affects the diaphragm, the symptoms may include chest, shoulder, and neck pain.

In this article, we provide an overview of this condition, including its symptoms, complications, and treatment.

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Diaphragmatic endometriosis is extremely rare. In most cases, endometriosis affects the pelvic organs and structures close to the uterus.

Estimates suggest that endometriosis affects 10–15% of all women of reproductive age and 70% of women with chronic pelvic pain.

However, it is difficult to get accurate estimates because people who have the condition but no symptoms may never receive a diagnosis. As the diagnosis of endometriosis is challenging and often slow, some people with symptoms may also not receive a diagnosis.

An estimated 12% of people with endometriosis experience symptoms of the condition outside of the pelvic area. However, researchers do not know the precise prevalence of diaphragmatic endometriosis.

Alongside discomfort and stiffness, diaphragmatic endometriosis primarily causes pain, which usually becomes worse at certain times of the menstrual cycle.

The symptoms can include:

  • chest pain and stiffness
  • shoulder pain and stiffness
  • neck pain and stiffness
  • difficulty breathing or a bloody cough in severe cases

A 2021 survey asked 136 members of endometriosis patient associations in 14 countries about their diaphragmatic endometriosis symptoms. Of the respondents, 68% reported moderate-severe pain in the upper abdomen. In addition, 64% had pain in the chest, and 54% had pain in the shoulder. More than half of the respondents had pain on the right side, whereas 11% had it on the left side, and 35% experienced bilateral pain.

The symptoms are usually worse during or before menstruation. This may be because the glands in the endometrial-like tissue respond to reproductive hormones, meaning that they cycle and shed along with the endometrial tissues.

Possible symptoms of endometriosis that affect the pelvic organs include:

  • pelvic pain
  • pain in the lower back and abdomen
  • pain during or after sex
  • heavy, painful periods
  • pain when going to the bathroom
  • feeling extremely sick and fatigued

Diaphragmatic endometriosis often occurs with other types of endometriosis, which can sometimes result in difficulty becoming pregnant or even infertility.

Surgery to remove the tissue interfering with pregnancy may help increase the likelihood of conception.

Hormone therapies can help reduce the symptoms of endometriosis, but they cannot reverse infertility.

There may be a higher chance of pregnancy through in vitro fertilization (IVF), especially after surgery.

One complication of diaphragmatic endometriosis is difficulty getting pregnant. In some cases, pregnancy may not be at all possible.

The surgical procedures that doctors use to treat endometriosis are associated with health risks, as with all surgeries.

Possible complications associated with endometriosis surgeries include:

  • bleeding
  • bruising
  • infection
  • organ or tissue damage
  • regrowth of abnormal tissues
  • blood clots in the legs or lungs

Diaphragmatic endometriosis may cause additional complications in very rare cases because of the role the diaphragm plays in breathing.

Additional complications may include:

  • restricted breathing
  • collapsed lung
  • fluid, blood, or air in the chest cavity

Endometriosis may also contribute to someone developing depression. In these cases, a doctor may suggest a counselor or support group.

Researchers do not fully understand why endometriosis happens. However, there are many theories, including:

  • Abnormal circulation of endometrial cells: This is when the cells that line the uterus enter into circulation through the bloodstream or the lymph system, which is a series of interconnected immune glands.
  • Immune conditions: Medical conditions that interfere with the body’s natural defense systems may play a role in excess tissue growth and chronic inflammation.
  • Metaplasia: Metaplasia is when one type of cell randomly transforms into another.

Doctors usually diagnose diaphragmatic endometriosis after asking a person about their symptoms and carrying out tests, such as an MRI scan or a pelvic ultrasound.

During a pelvic ultrasound, a doctor will insert an ultrasound wand into the person’s vagina to look for cysts on the ovaries and other changes that may be associated with endometriosis.

Surgery is necessary to confirm the diagnosis, as the doctor will need to remove samples of the affected tissue and send them to a pathology lab to check.

There is currently no cure for endometriosis, but treatments can significantly reduce the symptoms.

The following factors will determine the best treatment options for a person:

  • severity of symptoms
  • severity or extent of the abnormal tissue growth
  • age of the individual
  • desire to become pregnant

Mild symptoms may respond to over-the-counter anti-inflammatories and not require any additional medical treatments.

However, for severe symptoms, a doctor will often prescribe hormone therapy in the form of either a pill, an injection, or a vaginal ring.

Some hormone treatments prevent ovulation, reducing the growth and activity of the endometrial-like tissue. These can sometimes reduce the symptoms.

A common treatment is birth control pills, which make menstrual periods shorter and light and can provide pain relief.

Laparoscopic surgery

For severe symptoms or symptoms that do not respond to hormone medications, surgical procedures may help.

The most common surgery for endometriosis is laparoscopy. During a laparoscopic procedure, the surgeon inserts a tube with a light and camera on one end through a tiny incision near the bellybutton. The surgeon will be able to see the location of the growths and determine their size and thickness.

Most surgeons will collect a small piece of the abnormal tissue. If an individual has already consented to tissue removal, the surgeon may also remove the growths.

Abdominal surgery

Diaphragmatic endometriosis may require abdominal surgery, either instead of or in addition to laparoscopic surgery.

The surgeon will make incisions in the abdominal wall that allow them to peel back layers of tissue and access the diaphragm. They will then locate and remove the growths.

Abdominal surgery involves larger incisions and full anesthesia, and it affects a much wider area of the body. As a result, it is associated with more serious complications.

Only severe diaphragmatic endometriosis usually requires surgery.

Video-assisted thoracoscopic surgery (VATS)

A VATS procedure is a type of keyhole surgery. In cases of diaphragmatic endometriosis, it allows the doctor to see the entire diaphragm.

In this procedure, a surgeon inserts a small camera through a tiny incision in the chest. The procedure can aid diagnosis, as well as making it possible for the surgeon to perform an operation on the affected area.

Alternative therapies and lifestyle habits may help decrease symptoms in some individuals, although these are not first-line treatment options. They include:

  • acupuncture
  • massage therapy
  • meditation
  • regular exercise
  • a diet rich in fresh fruits and vegetables and low in red meat and refined carbohydrates
  • proper hydration
  • no or minimal use of alcohol, caffeine, and nicotine
  • steps to reach or maintain a moderate body weight
  • stress management techniques

Below, we answer some common questions about diaphragmatic endometriosis.

Can diaphragmatic endometriosis be fatal?

If diaphragmatic endometriosis interferes with a person’s ability to breathe or leads to pneumothorax, it could potentially be fatal without treatment. However, as it is a very rare condition, there is little research that sheds light on its mortality rate.

Where can I learn about people’s experiences of diaphragmatic endometriosis?

Diaphragmatic endometriosis is a rare variant of endometriosis. People keen to learn more can read this 2018 case report or find some personal accounts on Livingwithendometriosis.org and endofound.org.

Endometriosis is a common condition that results from endometrial-like tissue growing outside of the uterus, including — in rare cases — on the diaphragm.

Although diaphragmatic endometriosis may not cause symptoms, severe growths can cause chest, neck, and shoulder pain and interfere with breathing.

Anyone experiencing pain in the abdomen and chest should speak with a doctor. This symptom may indicate diaphragmatic endometriosis, especially if it gets much worse before or during menstruation.