A case of catamenial pneumothorax

Pneumothorax is characterized by the presence of air in the pleural cavity, and it is a frequent pathology in an emergency department. Different forms of pneumothorax can be distinguished: spontaneous, post-traumatic, iatrogenic (associated with invasive maneuvers). Spontaneous pneumothorax is distinguished in: primary (in the absence of a pulmonary pathology), secondary (with a pulmonary pathology known as cystic fibrosis, chronic obstructive pulmonary disease, pulmonary tuberculosis) and catamenial. The latter affects the female sex and it is associated with the menstrual cycle. Catamenial pneumothorax is part of a more complex syndrome: thoracic endometriotic syndrome. It affects women between 30 and 40 years, the right lung is most involved and it occurs within 24-72 hours after the onset of menstruation. The pathogenesis is that of endometriosis, i.e. there is a dissemination of endometrial tissue outside the uterine cavity. In catamenial pneumothorax, endometriotic tissue is located at the level of the pleurae, the lung or the diaphragm. The most accepted theory is that endometrial tissue follows the circulation of peritoneal fluid. This theory explains why the endometrial lesions located at the diaphragmatic level concentrate mainly in the right hemi-diaphragm and from there they reach the pleura. From the clinical point of view the symptoms of the various forms of pneumothorax are: dyspnea, cough, chest pain, tachycardia, tachypnea and subcutaneous emphysema. The diagnosis is based on the physical examination, on the execution of an arterial blood gas that shows hypoxemia and on instrumental investigations. Today the ultrasound is important, already performed by the emergency doctor, which highlights the typical signs of the pathology (absence of gliding and identification of the lung point). The other instrumental tests are chest X-ray and CT scan of the chest. There are mild or severe forms of pneumothorax, in the former the treatment is based on clinical observation and evaluation of the evolution of pneumothorax; in severe forms the treatment is the placement of a drainage. The treatment of the various forms of pneumothorax is represented by: pleurodesis, sub-total pleurectomy and talcage which offer the best results in terms of prevention of recurrences. In addition, in the catamenial form the patient can undergo hormonal therapy. In this clinical case we describe a case of catamenial pneumothorax, which affects a 37-year-old woman who previously had a spontaneous pneumothorax. It is important when diagnosing a pneumothorax in the female sex to think of the catamenial form, which may not be a rare occurrence.