Thoracic endometriosis, the presence of endometrial tissue in the thoracic region, may in rare instances lead to pneumothorax in the left lung of young women, according to a case study. This condition, characterized by the presence of air or gas in the pleural cavity, can cause the lung to break from the chest wall.
The study,“Two Young Women With Left-Sided Pneumothorax Due To Thoracic Endometriosis,” was published in the journal International Medicine.
Pneumothorax is associated with thoracic endometriosis (TE), and usually affects women around the age of 30, occurring in the right pleural cavity. However, in their study, researchers in Japan reported the unusual cases of two young women who developed TE associated left-sided pneumothorax.
Case 1 was a 15-year-old girl who complained of chest pain and dyspnea that began with a menstruation cycle. A chest radiography revealed the presence of left-sided pneumothorax, severe enough that the patient was admitted for emergency thoracic drainage. Further analyses showed the presence of endometrial tissue that was positive for the progesterone receptor, which led doctors to diagnose the patient with TE.
The girl underwent surgery to remove the endometrial lesions and resect lung tissue. Despite the absence of pelvic lesions, a gynecologist recommended gonadotropin-releasing hormone (GnRH) analog therapy, but this treatment was declined by the patient and her parents. Twenty-two days after the surgery, the patient had no sign of the left-sided pneumothorax and remained healthy throughout a one-year follow-up.
Case 2 was a 20-year-old woman presenting left-sided pneumothorax with air leakage for the last 10 days, that had been drained by her general practitioner. She was also on the first day of a menstruation cycle when she was admitted to the hospital. Similar to the previous case, medical analyses revealed the presence of endometrial tissue in the lung, positive for the progesterone receptor, which helped in the diagnosis of TE. The patient accepted the recommendation for GnRH analog therapy by a gynecologist, despite the absence of pelvic lesions. Six months after the treatment, the patient remained stable.
“Reports of endometriosis-related pneumothorax in young women are rare, and the prevalence among women of all ages remains unclear,” the researchers wrote. “Pneumothorax due to TE can thus be difficult to diagnose without surgical exploration.”
According to the authors, a TE diagnosis requires the presence of endometrial tissue or the positive expression of hormone receptors, such as estrogen or progesterone receptors. It may be possible that the number of TE-related left-sided pneumothorax is currently underestimated.
“[T]he prevalence of TE-related pneumothorax in teenage girls and young women may be underestimated if the case is treated as spontaneous pneumothorax,” they concluded. “Although the mechanisms underlying the dissemination to or the implantation of endometrial tissue in the thoracic cavity in these age groups are still not well understood, they likely differ from the mechanisms causing TE that affects patients in other age groups.”