Pulmonary endometriosis is a rare disease of uncertain pathogenesis which generally presents with the cyclic clinical symptoms and catamenial changes noticed on computer tomography during menstruation. We report a case of a 33-year-old woman with recurrent hemoptysis for 1 year. The patient did not exhibit a temporal relationship between her periods and the onset of hemoptysis. A chest computed tomography scan showed multiple pseudocavities in the lower lobe of the right lung and multiple nodules in both lower lobes of the lungs. The right lower lobe wedge resection was performed. Postoperative pathological examination showed pulmonary endometriosis which is a rare cause of hemoptysis.

Pulmonary endometriosis (PEM) is rare, and drug therapy remains the primary treatment. However, patients with PEM frequently experience recurrent hemoptysis that is refractory to pharmacological intervention. We herein describe a patient with PEM who developed recurrent hemoptysis and was successfully treated with photodynamic therapy (PDT) after drug withdrawal. The patient was admitted to our hospital because of recurrent hemoptysis despite repeated drug treatments for more than 1 year. Given that PDT targets specific tissues and destroys vascular endothelial cells through the cytotoxic effect produced by the photodynamic reaction of the photosensitizer, we considered that it may effectively control hemoptysis secondary to vascular morphological changes in PEM. Therefore, we performed PDT in this case, and the patient\'s recurrent hemoptysis regressed. Approximately 2 years following PDT, the patient had recovered well and reported no discomfort. We recommend consideration of PDT as a treatment option for patients with PEM who develop recurrent hemoptysis after drug withdrawal. Notably, the patient\'s lung lesions should be superficial and limited, and no contraindications should be present.

Pulmonary endometriosis is a rare form of thoracic endometriosis. We herein describe a 29-year-old woman with recurrent hemoptysis associated with her menstrual cycle. The patient had a 4-month history of catamenial hemoptysis without thoracic pain, respiratory embarrassment, cough, fever, night sweating, or loss of appetite. Chest computed tomography revealed exudation shadows in the right lower pulmonary lobe and small fiber lesions in the right middle lobe and left lung. Thoracoscopic wedge resection of the right lower pulmonary lobe was performed, and the pathological result was pulmonary endometriosis. No evidence of hemoptysis during menstruation was found following the operation.