Can thoracic endometriosis cause pleural effusion?

Yes. Thoracic endometriosis can irritate tissues in and around the chest and, in some cases, lead to abnormal fluid in the pleural space (the thin space around the lungs). More classically, thoracic endometriosis syndrome is linked to cyclical chest pain and shortness of breath, recurrent lung collapse around the menstrual cycle, and—more rarely—bleeding into the chest (a hemothorax), but fluid around the lung can be part of the picture.

What raises suspicion is timing: symptoms and imaging findings that predictably worsen just before or during periods, especially if they recur and don’t fit more common explanations. Because standard imaging can show fluid but not reliably prove endometriosis, diagnosis often depends on connecting the menstrual pattern to the chest findings and, when appropriate, confirming disease surgically (sometimes in coordination with thoracic surgery). If you’re dealing with recurrent pleural fluid or cyclical chest symptoms, our team can help you evaluate whether thoracic endometriosis could be contributing and talk through medical and surgical options.