Catamenial pneumothorax in sisters.

Two sisters had documented pelvic endometriosis and catamenial pneumothoraxes. Both were typical of the 54 reported cases of catamenial pneumothorax in that pneumothoraxes were always on the right and occurred only at menses with onset in the fourth decade. One patient was asymptomatic during 11 months of menstrual suppression with hormones but subsequently required surgery where diaphragmatic perforations were found. The other patient was treated with isoxazole ethisterone with no pneumothoraxes while under suppression. These patients are unlike any of the previously reported cases of familial pneumothoraxes. We have not found a previous report of a familial catamenial pneumothorax.