Catamenial Pneumothorax, a Commonly Misdiagnosed Thoracic Condition: Multicentre Experience and Audit of a Small Case Series With Review of the Literature.

BACKGROUND: Catamenial pneumothorax (CP) is an unusual condition affecting premenopausal women and commonly misdiagnosed as simple pneumothorax. It is characterised by its recurrence between the day before and within 72 hours after the onset of menstruation. It has been associated with thoracic endometriosis but the aetiology is not well understood and there is no unified agreement for its optimal management. The aim of this study is to determine the incidence of CP in surgical patients and the results of their treatment.

METHODS: Females between the ages of 30 to 50 years with a diagnosis of pneumothorax, admitted for surgery over a 10-year period in four different hospitals were retrospectively reviewed for evidence of CP. An audit of surgical and medical management of the patients with CP and their short to midterm outcomes was performed in addition to a systemic review of the literature on CP.

RESULT: A total of 120 premenopausal female patients with a diagnosis of pneumothorax were admitted for Video Assisted Thoracoscopic (VAT) surgery and five women (4.1%) with a mean age of 42.6 years were diagnosed to have CP through surgical and histological findings. The first case was diagnosed 5 years ago and the last three within recent 12 months after the changes in surgical practices of inspecting diaphragmatic surface in suspected cases of CP. Four patients underwent diaphragmatic plication and one patient had a pleural biopsy. All patients underwent talc pleurodesis and hormone therapy in the postoperative period. Short to midterm (mean follow-up period of 25.2 months) results of the patients with CP were encouraging.

CONCLUSIONS: It is possible that many of the cohort of premenopausal female patients presenting with recurrent pneumothorax are misdiagnosed as spontaneous pneumothorax (SP) because routine inspection of the diaphragmatic surface is not often performed. A thorough menstrual history and its temporal relation to pneumothorax onset should be assessed on every woman presenting with recurrent pneumothorax and intraoperative exploration of diaphragmatic surface should be performed in the patients with high suspicion of CP as the patients diagnosed with CP have a good outcome with surgery and hormone therapy.