**4. Clinical manifestations and diagnosis**

The typical clinical manifestations of CPX include spontaneous pneumothorax with or before menses presented with pain, dyspnea, and cough. Scapular and thoracic pain may also be present before or during menstruation. There may also be a history of previous episodes of spontaneous pneumothorax, history of previous uterine surgery, primary or secondary infertility or uterine scratching, pelvic

endometriosis diagnosis, and history of catamenial hemoptysis or catamenial hemothorax [30].

Medical history and occurrence of typical symptoms are crucial for the diagnosis of catamenial pneumothorax, and these findings should be systematically investigated [11]. Although existence of these findings creates high suspicion on catamenial pneumothorax, their absence does not exclude a diagnosis of catamenial pneumothorax [24, 30].

Intermittent presentations out of menstrual bleeding time should not exclude the diagnosis of noncatamenial endometriosis-associated pneumothorax even in the absence of symptoms and pelvic endometriosis [9, 24, 38].

The clinical course of CPX is usually mild or moderate, but sometimes be life-threatening. Widespread thoracic endometriosis after previous operations is reported in the literature as case reports [39]. A young woman who experienced an episode of life-threatening hemopneumothorax who has been treated by urgent tube thoracostomy and thoracotomy was reported by Morcos et al. [39]. Lung wedge resection, parietal pleurectomy, and partial diaphragmatic excision have also been performed in this case.

Patients with CPX are reported to have a mean age of 35 (range 15–54) years at presentation [40].

Catamenial pneumothorax can also have very rare presentations in the literature. Simultaneous occurrence of pneumoperitoneum and catamenial pneumothorax [33, 34], catamenial pneumoperitoneum mimicking acute abdomen in a woman with multiple episodes of pneumothorax [35], pneumothorax, and pneumoperitoneum in a patient with spontaneous diaphragmatic rupture has been reported in the literature [41].

Medical history is the main pathway on the way to the diagnosis of CPX. Synchronicity of the clinical course with menses is the main character of the disease, but on the other hand intraoperative visual inspection and appropriate histological examination of the pathognomonic lesions are crucial for the diagnosis of endometriosis-related pneumothorax. The surgeon needs to be vigilant because it can easily be missed if not cautious [7, 24, 29, 42].
