Catamenial pneumothorax.

Thoracic endometriosis syndrome is an under-recognised manifestation of endometriosis and includes catamenial pneumothorax, catamenial haemothorax, catamenial haemoptysis and pulmonary nodules. Catamenial pneumothorax presents as recurrent spontaneous pneumothorax with a temporal relationship to the onset of menses, affecting mostly the right lung. A 48-year-old woman presented with an eight-year history of right-sided catamenial pneumothorax, during which time she had three episodes of pneumothorax. Serial chest imaging revealed an enlarging mass overlying the right hemi-diaphragm. She was referred to our trust where she underwent video-assisted thoracoscopic surgery for right pleurectomy. Intraoperatively, defects were found in the right hemidiaphragm, through which parts of the liver had herniated. We describe the presenting features and management of catamenial pneumothorax.