What is thoracic endometriosis?
Endometriosis is a chronic condition in which tissue similar to the lining of the womb is found elsewhere in the body. Thoracic endometriosis refers to endometriosis involving the chest, which may include the diaphragm, lungs, pleura (the lining around the lungs) and pericardium (the sac around the heart).
“Thoracic endometriosis syndrome” is often used for a group of chest presentations associated with endometriosis. Arguably, the best recognised presentation is catamenial pneumothorax, a collapsed lung occurring timely with menstruation. Other recognised presentations include blood in the pleural space, coughing up blood and cyclical chest or shoulder pain.
A note about timing
“Catamenial” usually describes symptoms close to the onset of menstruation. Thoracic endometriosis can still be considered when timing is less exact, cycles are suppressed or irregular, symptoms occur outside menstruation, or a person does not currently menstruate. A clinician must assess the whole history.
Possible symptoms and presentations
- Sudden or recurring chest pain, often (but not always) on one side.
- Shortness of breath, tightness in the chest, or difficulty taking a deep breath.
- Shoulder-tip, shoulder-blade, neck, jaw, rib or upper abdominal pain.
- Pneumothorax, including repeated pneumothoraces.
- Blood or fluid collecting around a lung.
- Cough, including coughing up blood.
- Symptoms that recur in a hormonal or menstrual pattern.
- Symptoms of pelvic endometriosis, although these may be absent or undiagnosed.
Please note, symptoms are not limited to this list. Symptoms have many possible causes, some of which are emergencies. The presence of one or more symptoms does not confirm thoracic endometriosis.
What is a pneumothorax?
A pneumothorax occurs when air enters the space between a lung and the chest wall, allowing part, or all of the lung, to collapse. Symptoms can include sudden or different chest pain, breathlessness or noticeable discomfort on inhale. Pneumothorax needs clinical assessment and may require observation, imaging, oxygen, aspiration, a chest drain or surgery, depending on its size, cause and effect on the person.
What does “catamenial pneumothorax” mean?
Catamenial pneumothorax describes a pneumothorax that typically occurs in a defined time window around the start of menstruation or ovulation. Published definitions commonly use the period from 1 to 2 days before to 3 days after menstruation begins, or around the time of ovulation. Real clinical cases can be less rigid with timings. Timing alone neither confirms nor excludes thoracic endometriosis.
How is thoracic endometriosis assessed?
Assessment may include a detailed history, review of hormonal timing, previous or new imaging, physical examination and tests chosen for the current symptoms. Other conditions may also need to be ruled out. Chest X-ray or CT may identify a pneumothorax or other chest abnormality. MRI may also be used, especially for assessment around the diaphragm.
Imaging can show as ‘clear’ or ‘normal’ results. Imaging cannot always identify endometriosis deposits.
Some people are diagnosed or treated during video-assisted thoracoscopic surgery (VATS) or robot-assisted thoracoscopic surgery (RATS). A combined assessment may involve thoracic surgery, gynaecology, respiratory medicine and radiology.
Treatment
There is no cure for any type of endometriosis. Treatment options are available as management tools only. These may involve hormonal medications, surgery, pain relief, lifestyle adjustments, physiotherapy, or a combination of approaches. Thoracic surgery procedures may address a pneumothorax and visible abnormalities, but there is no guarantee of improvement in symptoms. Gynaecological assessment may also be relevant. Benefits, limitations, recurrence risk, side effects, fertility considerations and personal preferences should be discussed with your medical team.
Thoracic Endo Co does not recommend a specific treatment or clinician. Decisions should be made with qualified healthcare professionals who know your history.
What current guidance says
NICE guideline NG73 provides guidance on the diagnosis and management of endometriosis. Thoracic endometriosis was originally excluded from its scope because it was considered rare. In 2021, NICE undertook an exceptional surveillance review, which identified insufficient evidence to develop specific recommendations for diagnosing and managing endometriosis outside the pelvis. Although NG73 does not provide detailed guidance on thoracic endometriosis, it recommends referral to a specialist endometriosis service for suspected or confirmed endometriosis outside the pelvic cavity.
The European Society of Human Reproduction and Embryology (ESHRE) Endometriosis Guideline (2022) includes recommendations on thoracic endometriosis, while acknowledging the limited evidence available. It advises that diagnosis and treatment should be discussed by a multidisciplinary team with appropriate expertise, with thoracic surgeons involved when surgery is indicated. It also highlights symptoms clinicians should recognise, including cyclical shoulder pain, cough and pneumothorax (lung collapse).