Thoracic endometrial syndrome with unilateral exudative pleural effusion

A woman in her 40s presented with exertional dyspnoea with an absence of haemoptysis, cough, fever and weight loss. The patient had a medical history of extensive endometriosis. Investigations revealed a large right-sided pleural effusion. The effusion was aspirated and was exudative in nature.A contrast-enhanced CT thorax was performed to help exclude dual pathology. The only positive finding was bilateral breast nodules, subsequently found to be benign fibroadenomas on histological analysis of biopsy samples.After malignancy was ruled out as a cause, the patient was referred for medical thoracoscopy for a biopsy and other investigations. Histology demonstrated the presence of endometrial tissue in the pleura and thereby confirmed the diagnosis of thoracic endometrial syndrome.Video-assisted thoracoscopic surgery repair of diaphragm and talc pleurodesis was carried out in an uncomplicated procedure and the patient was discharged with good recovery.