Massive hemothorax due to diaphragmatic endometriosis after a laparoscopic cystectomy of an ovarian endometrioma in a patient without a history of thoracic endometriosis.

Background: Severe hemothorax is a rare complication after laparoscopic surgery for endometriosis, and the causes and proper management are not well understood.

Case: We report here the extremely rare case with massive hemothorax after laparoscopic surgery for ovarian endometrioma. A 40-year-old woman, gravida 1, para 1, underwent laparoscopic cystectomy of ovarian endometrioma. On postoperative day 2, she had progressive anemia (Hb 5.3) as well as dyspnea. A chest X-ray and computed tomography showed massive fluid collection in the right thoracic cavity, suggestive of intrapleural bleeding.

Treatment: Thoracoscopic operation was performed and a total of 930 ml of blood retention in the right thoracic cavity was found. Scattered small endometriotic lesions were present on the pleural surface of the right diaphragm; pulsatile active bleeding was confirmed from one of these. Furthermore, two endometriotic lesions had perforated into the intraperitoneal cavity. The diaphragm containing bleeding spots was thoracoscopically resected and sutured. After thoracoscopic surgery, the dyspnea and anemia resolved. On postoperative day 5, the patient left the hospital.

Conclusion: The present report reminds us of the importance of paying special attention to postoperative-thoracic complications caused by diaphragmatic endometriosis if the patient shows respiratory symptoms.