Catamenial pneumothorax and endometriosis-related pneumothorax: clinical features and risk factors.

BACKGROUND Catamenial pneumothorax and thoracic endometriosis (TE) are still under diagnosed. The purpose of this study is to increase the diagnostic accuracy for these conditions in patients with spontaneous pneumothorax and to identify their risk factors. METHODS We conducted a retrospective study on all consecutive women of reproductive age referred to our Centre for surgical treatment of spontaneous pneumothorax between July 2000 and January 2009. RESULTS The study population comprised 156 premenopausal women of whom 49 (31.4%) had catamenial and/or TE-related pneumothorax. Over a quarter of these 49 patients had a previous history of recurrent thoracic or scapular catamenial pain. They experienced their first pneumothorax episode at an older age (mean ± SD) (34.0 years ± 6.7) than women with idiopathic pneumothorax (28.7 ± 6.1 years, P < 0.001). Pelvic endometriosis was found in 51% of women with catamenial and/or TE-related pneumothorax. After adjustment for confounding factors by multiple logistic regression analysis, the results show that, infertility [odd ratio (OR) = 4.21, 95% confidence interval (CI) = 1.28-13.88] and a history of pelvic surgery with a uterine procedure and/or uterine scraping (OR = 2.85, 95% CI = 1.12-7.26) were the strongest predictors of catamenial and/or TE-related pneumothorax. CONCLUSIONS Infertility and uterine procedures are significantly associated with catamenial and/or TE-related pneumothorax. Scapular or thoracic pain during menses often precedes the occurrence of pneumothorax and is highly specific for the diagnosis of TE. Our results suggest that in women with pelvic endometriosis, these symptoms should be systematically investigated for an earlier diagnosis of TE.