Recurrent pneumothorax was associated with the menstrual cycle in two women 20 to 30 years age; this is
referred to as catamenial pneumothorax. This form of pneumothorax occurs within 72 hours before or after the
onset of menstruation. The pathophysiology underlying this condition is unknown. We report here on two cases of
catamenial pneumothorax that were successfully treated by partial resection of the diaphragm