Meigs syndrome after treatment for catamenial pneumothorax

In the field of thoracic surgery, catamenial pneumothorax (CP) is known as a disease peculiar to women, but it is rare among female pneumothoraces and is rarely encountered in clinical practice. Meigs syndrome (MS) is another female-specific disease, defined as a benign ovarian tumor with pleural and ascites effusions, but it is rare and the details of the pathogenesis of MS have not yet been elucidated.A 40-year-old Japanese woman came in with dyspnea. Chest radiography revealed a collapsed right lung. She underwent video-assisted thoracoscopic surgery, which revealed multiple diaphragmatic foramens. She was therefore diagnosed with CP. Later, when she was 50-year-old, returned with chest pain. Computed tomography of the chest and abdomen showed right massive pleural effusion and a large tumor and ascites in the pelvis. This condition was suggestive of MS. The patient underwent bilateral oophorectomy, and the right pleural effusion and ascites resolved promptly after surgery.In conclusion, both menstrual-associated CP and MS are very rare conditions, and to the best of our knowledge, there are no reported cases of the combination of the two. However, it is possible that some MS patients may have MS without CP, and the present case is considered to be valuable because a small diaphragmatic foramen was identified via thoracoscopy, which has been a minority opinion among the mechanisms of pleural effusion in MS.