I read with great interest the selected report by Puma et al1in a recent issue of CHEST (September 2003). They described a case of endobronchial endometriosis that was successfully treated by Nd-YAG laser therapy. However, I would like to suggest that pulmonary endometriosis is probably less rare than is commonly thought, as I have counted 104 cases of tracheobronchial or pulmonary endometriosis as a result of searches of the medical literature (including 23 cases published in languages other than English). Some of these cases presented evidence such as a pattern of lung opacities or necropsy findings and not catamenial hemoptysis. I also think that Nd-YAG laser therapy could be useful for the treatment of endobronchial endometriosis only when drug therapy is not effective, or when the adverse effects of this drug therapy are intolerable, as this procedure is associated with a certain morbidity. Although the risk of general anesthesia is considered to be low, hypoxemia, hypercapnia, and acidosis secondary to apneas, and the reduction of ventilation are presumed to be the major causes of intraoperative and postoperative complications.2 Cardiac arrest due to ventricular fibrillation may occur during rigid bronchoscopic laser therapy even in young patients with benign bronchial lesions.3The authors maintained that “Medical therapy has been recommended as the first choice in pulmonary endometriosis. It consists of the suppression of endometrial tissue with progesterone (ie, pseudopregnancy) or danazol (ie, pseudomenopause).” I only partly agree with this statement, as the authors failed to mention that gonadotropin-releasing hormone agonists have been prescribed for > 10 years and are effective in the treatment of this disease, as in our published case.5 Finally, I think that the follow-up period was not sufficiently long enough to ensure that the treatment was permanently effective. Unfortunately, the authors did not mention whether follow-up fiberoptic bronchoscopy was performed during menses.