Catamenial Pneumothorax (Thoracic Endometriosis) in 38-year-old Woman

This is an answer to the case – Woman with Recurrent Right-Sided Chest Pain Synchronously with her Menses

A 38-year-old female smoker reported having had intermittent, recurrent right-sided chest pain for several months. Pelvic endometriosis had been diagnosed during laparoscopy for in vitro fertilization 6 years earlier.

Six months before presentation, a small, right-sided spontaneous pneumothorax had been diagnosed for which she received no treatment; follow-up chest radiography 2 weeks later revealed no abnormalities.

She was admitted because of acute dyspnea, and a recurrent right-sided pneumothorax was diagnosed. It was her second day of menstruation, and she remembered that the first episode of pneumothorax had also taken place on the second day of her menstrual cycle.

Spiral computed tomography of the thorax showed no abnormalities. Video-assisted thoracoscopy on the fifth day of menstruation showed numerous brownish oval lesions scattered on the diaphragm, a finding diagnostic of endometrial implants (Thoracic Endometriosis), implicating catamenial pneumothorax as the cause of her chest pain. These lesions may vary in size during the menstrual cycle and may disappear altogether.

During thoracoscopy a talc poudrage was applied, and treatment with a gonadotropin-releasing–hormone analogue was started. Menstruation stopped, and the chest pain disappeared. During a 6-month follow-up period, pneumothorax did not recur.