This article on Epainassist.com has been reviewed by a medical professional, as well as checked for facts, to assure the readers the best possible accuracy.

We follow a strict editorial policy and we have a zero-tolerance policy regarding any level of plagiarism. Our articles are resourced from reputable online pages. This article may contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

The feedback link “Was this Article Helpful” on this page can be used to report content that is not accurate, up-to-date or questionable in any manner.

This article does not provide medical advice.


What is Thoracic Endometriosis & How is it Treated? | Causes, Symptoms and Diagnosis of Thoracic Endometriosis

What is Thoracic Endometriosis?

Thoracic endometriosis is a condition in which endometriosis-like patches grow on and around the lungs.

Endometriosis is a common condition affecting 6-10% of females of reproductive age.(1) In it, tissue similar to that lining the uterus grows outside the uterus. Mostly these endometrial patches grow in the abdomen and pelvic region.

In thoracic endometriosis, these patches grow on or around the lungs. It is observed, that among people with endometriosis, 12% have patches of tissues growing outside reproductive organs. This is called extragenital endometriosis.

Thoracic endometriosis is the most common extragenital endometriosis. it can occur on its own, but it is seen that more than half of the people with thoracic endometriosis have endometriosis in the pelvic area. These patches swell and bleed during menstruation.

Causes of Endometriosis

What causes endometriosis is not clear but, there are numerous theories associated with it.

One reason is retrograde menstruation. It happens when the menstrual blood travels backward through the fallopian tubes instead of flowing out of the body through the vagina, which then accumulates in the abdomen. It is theorized that this menstrual blood mixes with endometrial patches of the tissue causing more patches farther up in the abdominal cavity and lungs.

It is still not clear why thoracic endometriosis occurs. Only a small percentage of people with retrograde menstruation have endometriosis.(2)

Symptoms of Thoracic Endometriosis

Some people with thoracic endometriosis have no symptoms.(1) If symptoms are present they depend on the location of endometriosis.

Those with thoracic endometriosis may have the following condition and related symptoms.

Catamenial Pneumothorax

Pneumothorax means collapsed lung. It is a condition in which air leaks into the space between the chest wall and lungs.

Catamenial pneumothorax is a condition in which there is a recurrent collapsed lung within 72 hours or beginning of menstruation. It is known to occur in 80% of people with thoracic endometriosis.

The symptoms of catamenial pneumothorax include:

Catamenial Hemothorax

Catamenial hemothorax is a condition in which blood accumulates in the pleural space within the lining of the lungs. It affects the right lung more commonly.

This condition is known to occur in 14% of people with thoracic endometriosis and the symptoms resemble those of pneumothorax these include:

  • Cough
  • Chest pain
  • Shortness of breath

Catamenial Hemoptysis

Catamenial hemoptysis happens when there is repetitive bleeding in one or both the lungs. It mostly happens at the same time as menstruation. Changes in hormones cause the endometrial patch to swell and bleed.

It is known to occur in 5% of people with endometriosis.

The symptoms of catamenial hemoptysis include:

  • Shortness of breath
  • Chest pain
  • Coughing up of blood

Pulmonary Nodules

Pulmonary nodules are atypical growths on the lungs that can range from half a centimeter to 3 cm in diameter. These are very rare but can occur in some people with thoracic endometriosis. The symptoms may include:

  • Chest pain
  • Shortness of breath
  • Cough

Diagnosis of Thoracic Endometriosis

Diagnosing thoracic endometriosis is very difficult as identifying the relation between symptoms and a person’s menstrual symptoms is very difficult.(3)

A person may be having bouts of coughing, chest pain and shortness of breath. But one would not think about relating them to menstrual symptoms.

If thoracic endometriosis is suspected, they can ask to get the following test:

The test performed during menstruation can be compared with those done during the non-menses period of the person’s cycle. Any coinciding characteristics if seen, a diagnosis can be made.

How is Thoracic Endometriosis Treated?

The treatment for thoracic endometriosis involves medication and surgery.


The first line of treatment involves medications that suppress the ovarian hormone that further suppresses existing endometrial tissue and also slows the growth of new patches.

Medications do help but cannot cure the condition. It is observed that 60% of people with hormone suppression therapy have a recurrence in 12 months.(1)

The common medication prescribed are:

  • Gonadotropin releasing hormones
  • Oral contraceptives
  • Progestins
  • GnRH antagonists
  • Aromatase inhibitors


The surgery in this condition involves removal of patches of endometrium from the thorax via thoracoscopy. Diaphragmatic patches from the diaphragm are also removed with laparoscopy.

These are minimally invasive keyhole surgeries.

After the surgery hormonal medications are prescribed to slow down the growth of new patches.

If a person has recurrence with a combination of medicine and therapy, surgical removal of the uterus, ovaries, and fallopian tubes may be necessary. After the extensive surgery, a person may still need post-surgery hormone therapy.

Thoracic endometriosis is a rare condition that can lead to shortness of breath, chest pain, and collapsed lungs. It can be treated with a combination of surgery and medication. Regular treatment and check-ups can be helpful in managing the condition.

Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:July 6, 2022

Recent Posts

Related Posts