Thoracic endometriosis is a rare manifestation of extragenital endometriosis.1
Up to 60% of cases will be associated with pelvic endometriosis.1,8,9
Lesions on the diaphragm and visceral pleura are the most commonly described sites (38.8% and 29.6%, respectively).8
Lesions of the parenchyma are uncommonly encountered.1,9
Bilateral thoracic endometriosis is rare.
The exact pathophysiology of catamenial pneumothorax remains unclear. Three main theories have been proposed.10
The theory of retrograde menstruation suggests endometrial cells enter the peritoneal cavity and then enter the pleural space through lymphatic channels, diaphragmatic fenestrations or hematogenously as with metastatic disease. This theory was first described by Schron and Ruysh over 237 years ago.11
The hormonal model implicates high prostaglandin F2
at ovulation, which may result in vasospasm and associated ischemia in the lungs. This, in turn and in combination with prostaglandin-induced bronchospasm, may result in alveolar rupture and subsequent pneumothorax.12
Finally, the anatomic model suggests that the loss of the cervical mucus plug during menses results in communication between the environment, peritoneal cavity, and subsequently the pleural space.13
Diagnosis of thoracic endometriosis weighs heavily on clinical suspicion.9
Most patients will present with symptoms consistent with catamenial pneumothorax: shortness of breath, cough, and pleurisy. Chest radiograph, CT, MRI, thoracentesis, and bronchoscopy have been deemed useful in evaluating thoracic endometriosis. However, video-assisted thoracoscopic surgery (VATS) remains the gold standard for both definitive diagnosis and surgical treatment.13
Medical treatment is the first step in the management of symptoms; however, it can be expensive and recurrence is high with discontinuation. By contrast, chemical pleurodesis, pleurectomy, and segmental resection have all proven successful in the resolution of symptoms.14
The introduction of video-assisted endoscopic surgery has revolutionized modern day surgery.15
In the same vein, the use of VATS allows for direct visualization of implants and nodules throughout the thoracic cavity, and the ability to resect apical blebs, parenchymal, and diaphragmatic implants. Superficial implants can be treated using bipolar, CO2
laser or plasma energy. Exploratory thoracotomy, previously used regularly for diagnosis and treatment, now is reserved for cases in which minimally invasive techniques fail.
In this case, we used a multidisciplinary approach of VATS and VALS, thus optimally addressing pelvic, thoracic cavity, and subdiaphragmatic regions in a single operation.5
The minimally invasive, combined approach to thoracic endometriosis is gaining momentum as the mainstream surgical option for patients.