Recurring spontaneous pneumothorax concomitant with menstruation.

Details are given of nine cases of recurrent spontaneous pneumothorax concomitant with menstruation; of these, four are culled from the literature. In every case the time interval between the onset of menstruation and the development of a pneumothorax has been very close, and from the evidence presented some causal relationship is envisaged. Endometriosis is considered as a possible cause. Two of the patients had proven endometriosis of the diaphragm and this condition was almost certainly present in a third patient. Three patients had pelvic endometriosis. The pneumothorax always occurred on the right side, and the possible significance of this is discussed.