Abstract
The first report of the catamenial pneumothrax in Japan was presented. A fourty years old house wife has been affected with five times of the catamenial pneumothorax during the last three years. The right chest pain and/or bloody sputum have been also frequently experienced at the menstrual periods. By the thoracotomy, a pin hole perforation with a small yellow nodule was found in the right middle lobe. Although the characteristic findings of the endometriosis was not revealed in the lung biopsy specimen, the endometriosis of the umbilicus and the Douglas' cavity were detected by the surgical procedures as well as the bilateral ovarial chocolate cysts. Therefore, it is reasonable to think that the catamenial pneumothorax in this case is probably due to the intrathoracic endometriosis. The possible pathogenesis of the endometriosis and the catamenial pneumothorax was briefly discussed.
