Left-Sided Catamenial Pneumothorax with Thoracic Endometriosis and Bullae in the Alveolar Wall

Abstract

Catamenial pneumothorax (CP) is generally caused by intraperitoneal air leaking from the uterus into the thoracic cavity via a defect in the endometrial tissue of the diaphragm and is usually detected in the right thorax. We report a case of left-sided CP caused by endometriosis in the visceral pleura and with no abnormal findings in the diaphragm. A 33-year-old female patient presented at the end of a course of low-dose contraceptive pills for pelvic endometriosis, with spontaneous pneumothorax in the left chest. Chest CT revealed a bulla in the left upper lung lobe. The patient underwent partial resection of the lung. Immunohistochemistry confirmed the presence of endometrial stromal tissue in the visceral pleura and confirmed this as the cause of pneumothorax since there were no observable abnormalities in the diaphragm. This case suggests that immunohistochemical examination of patients with spontaneous pneumothorax can detect alternative endometrial lesions.

Keywords: catamenial pneumothorax; endometriosis; thoracic endometriosis syndrome.

Fig. 1

Chest CT (A, B), intraoperative findings of bulla (C) and diaphragm (D). (A, B) A bulla was found in the lateral portion of the left upper lung lobe. (C) There was a bulla on the upper lung lobe. (D) There was no detectable diaphragmatic lesion.

Fig. 2

Pathological findings (A) A cystic dilatation of the alveolar space associated with a mass of spindle-shaped cells spreading within the alveolar wall was found. Immunohistochemical analysis revealed the existence of endometrial tissue. Scale bar = 500 µm. (B) Hematoxylin staining, scale bar = 100 µm. (C) Immunostaining with an anti-estrogen receptor antibody, scale bar = 100 µm. (D) Immunostaining with an anti-progesterone receptor antibody, scale bar = 100 µm. (E) Immunostaining with an anti-CD10 antibody, scale bar = 100 µm.