Can thoracic endometriosis cause pleural effusion?

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

The timing raises suspicion: 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 cannot reliably prove endometriosis, diagnosis often depends on linking 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.