Pleural effusion secondary to endometriosis: A systematic review

Endometriosis-associated pleural effusion is a rare occurrence with poorly defined clinical characteristics. A systematic review was performed to examine all articles on endometriosis-associated pleural effusion extracted from 4 databases (PubMed, Embase, Web of Science and Scopus) from inception until November 2022. A total of 142 articles (isolated cases and small retrospective series) involving 176 patients (median age 33 years) with endometriosis-associated pleural effusion were included. The most frequent symptoms were dyspnea (67%), chest pain (55%) and abdominal pain (40%). Pleural effusion was predominantly unilateral (89%), right-sided (88.5%) and massive (56%). Ascites was evident in 42% of the cases. Pleural fluid had a bloody appearance in 99% of cases and always met the exudate criteria. Pleural fluid cytology identified only 9% of the patients, with pleural biopsy being the most common diagnostic procedure (74%). Most patients were treated with hormones (76%), thoracic surgery (60%) and abdominal surgery (27%). Effusion recurrence was observed in 26% of cases after a median follow-up of 1 year. The presence of right-sided hemorrhagic pleural effusion in a young woman warrants an assessment for the possibility of endometriosis. Despite conventional treatment, effusion recurs in approximately a quarter of patients.