What is Catamenial Pneumothorax

Catamenial pneumothorax is a rare, recurrent form of lung collapse that occurs in synchronization with the menstrual cycle, typically within 72 hours of the onset of menses. It is most commonly associated with thoracic endometriosis, where endometrial-like tissue migrates to the chest cavity, leading to air leaking into the space between the lung and chest wall.

What causes Catamenial Pneumothorax?

The exact mechanism of catamenial pneumothorax remains a subject of clinical research, but it is widely understood to be linked to thoracic endometriosis. The condition primarily affects the respiratory and reproductive systems. When endometrial tissue implants on the diaphragm or lung surface, it can cause small holes or cysts to form. During menstruation, hormonal changes may cause this tissue to bleed or slough off, creating a rupture that allows air to enter the pleural space, resulting in a collapsed lung.

Who is typically affected by this condition?

Catamenial pneumothorax is an extremely rare condition, primarily affecting women of reproductive age, typically between 30 and 45 years old. While exact global prevalence is difficult to determine due to underdiagnosis, it is considered a significant clinical challenge for those experiencing recurrent, period-related chest pain. At DiseaseMaps.org, we currently support 21 members who have shared their experiences with catamenial pneumothorax, helping to bridge the gap in patient-reported data.

How does this differ from other types of pneumothorax?

Unlike primary spontaneous pneumothorax, which often occurs without a clear underlying cause, catamenial pneumothorax is distinguished by its strict cyclical timing. Key differentiating factors include:

• Cyclical Timing: Symptoms appear exclusively or predominantly during the menstrual period.


• Endometriosis Link: Many patients have a history of pelvic endometriosis, though it is not present in every case.


• Anatomical Location: It most frequently affects the right lung (approximately 90% of cases), likely due to the movement of air or tissue through the diaphragm.

Next steps

• Consult a thoracic surgeon or a gynecologist specializing in endometriosis.


• Keep a detailed symptom diary tracking your menstrual cycle alongside any chest pain or shortness of breath.


• Connect with the 21 members of the DiseaseMaps.org community to share experiences and coping strategies.


• Discuss diagnostic imaging, such as high-resolution CT scans or video-assisted thoracoscopic surgery (VATS), with your medical team.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Thoracic Endometriosis Syndrome.


• Orphanet: Rare diseases database and clinical resources.


• PubMed: Current literature on the pathophysiology of catamenial pneumothorax.


• Endometriosis Foundation of America: Patient resources on thoracic manifestations.