Catamenial haemorrhagic pleural effusion caused by thoracic endometriosis, which was controlled by surgery undertaken after failed medical management

Haemorrhagic pleural effusion can be a challenging diagnosis that requires a thorough investigation and sometimes a multidisciplinary team of physicians to reach the underlying aetiology. Causes can include pulmonary malignancy, pulmonary infections, connective tissue diseases, asbestos associated, intra-abdominal conditions such as pancreatitis and ovarian tumours, cardiovascular disorders such as ruptured aneurysms and pulmonary infarction, as well as other miscellaneous causes. One such cause is endometriosis in the thoracic cavity. Endometriosis is a chronic illness associated with the occurrence of endometrial tissue outside the endometrium. Insertion of endometrial tissue in the thoracic cavity is rare, with only a few cases described. This case report gives detail of a 30-year-old nulligravida suspected of having thoracic endometriosis following a history of catamenial dyspnoea and associated pleural effusion. The diagnosis was confirmed through the histopathological study of tissue obtained via thoracoscopic surgery. Excision of the endometrial tissue was done, and the patient then continued medical treatment with progestins and gonadotrophin-releasing hormone (GnRH) agonists. Following therapy, the index patient was asymptomatic. A multidisciplinary approach is often needed in the diagnosis and management of thoracic endometriosis, involving both medical and surgical specialities. Minimally invasive surgery is the gold standard of diagnosis, allowing for direct visualisation of implants and nodules and should be followed by medical treatment to reduce the risk of recurrence. Medical therapy alone is associated with higher rates of recurrence. Physicians must have a high degree of suspicion as thoracic endometriosis is a disease that can often be missed.