Catamenial pneumothorax: a unique radiologic and intraoperative finding

Abstract

Catamenial pneumothorax is a relatively uncommon disease process, hallmarked by the presence of thoracic endometriosis causing cyclic spontaneous pneumothoraces. Identification of stigmata of catamenial pneumothorax on imaging is rare and is primarily limited to magnetic resonance imaging (MRI) or diaphragmatic components of the disease process. Evidence of the pleural component found on computed tomography (CT) has yet to be described in the literature. A 26-year-old female with past medical history of endometriosis presents with shortness of breath and pleuritic chest pain. Chest X-ray (CXR) denoted a significant right-sided hydropneumothorax for which a tube thoracostomy was placed. Subsequent chest CT scan noted the pneumothorax, absence of bullous disease, and the presence of apical pleural nodularity and associated pleural thickening. Persistent air leak mandated surgical exploration, and she underwent a right video-assisted thoracic surgery (VATS) which had unique findings. There were extensive web-like fibrotic bands throughout the parietal pleura, beginning at the apex and extending inferior laterally. Small darkened regions with nodular extensions, presumed thoracic endometriosis, were present on the lung parenchyma and parietal pleura. Pleurectomy with mechanical pleurodesis was performed along with apical wedge resections. Pathology denoted endometriosis within the pleural specimen. No symptoms have recurred in 5 months, and repeat CT scan denoted the absence of pneumothorax and good parietal-visceral pleural approximation. CT findings suggestive of catamenial pneumothorax are rare and are usually demonstrative of the diaphragmatic component of disease. Fibrous adhesive disease is rare as well and likely resultant of repeated inflammation, albeit the lack of previous symptoms or pneumothoraces. This case demonstrates not only a unique intraoperative finding but also a rare radiologic finding which may aid in the future diagnosis of pneumothorax from thoracic endometriosis.