Abstract
BACKGROUND: Catamenial pneumothorax is generally uncommon, with an incidence of less than 3-6% in women with spontaneous pneumothorax. As few cases of catamenial pneumothorax with diaphragmatic defect and liver herniation have been reported, this case report may be useful for understanding the cause and treatment. This case highlights the importance of the approach for liver hernia in patients with catamenial pneumothorax and endometriosis. CASE PRESENTATION: We report a case of catamenial pneumothorax in a 43-year-old woman with diaphragmatic partial liver hernia who was treated with thoracoscopic surgery. She was diagnosed with a right pneumothorax at menstruation onset. Chest computed tomography showed a nodule protruding above the right diaphragm. We performed thoracoscopic surgery to treat the persistent air leak and biopsied the nodule on the right diaphragm. There were blueberry spots on the diaphragm; the nodule was found to be the herniated liver. The diaphragmatic defect was sutured. Histological examination of the tissue near the partial prolapsed liver revealed endometrial tissue. CONCLUSIONS: It is speculated that ectopic endometrial tissue in the diaphragm will periodically necrose to become a diaphragmatic tear, which is a pathway for air to enter the thoracic cavity and eventually a herniated liver. Thoracoscopic surgery should be considered in patients with catamenial pneumothorax when a diaphragmatic lesion is suspected.