Abstract
A 46-year-old woman was diagnosed with pneumothorax and followed up. After that, she experienced chest pain during the menstrual period. The clinical course suggested catamenial pneumothorax. We performed an operation during the luteal phase owing to the patient's social background. The operation was carried out under thoracoscopy. A thinning cyst was observed on the middle lobe, and multiple holes were observed around the central tendon of the diaphragm, with blueberry-spots surrounding the area. The specimens showed stromal cells with positive staining for estrogen receptor, progesterone receptor, and CD10. The patient was therefore diagnosed with catamenial pneumothorax. The patient underwent hormone therapy and remains free of recurrence. Although we were unable to identify endometriosis lesions, immumnostaining served as a diagnostic tool.
