"Ask Dr. Cook" is a series of questions and answers regarding endometriosis. The current subject and answer can be found on Current Ask Dr. Cook web page. The questions may represent a summary of questions I have been asked by several different patients. I hope you find this information helpful. If you have a question you would like answered, please Submit A Question.

Endometriosis of the Lung

Question:
I've been told that endometriosis can spread outside of the pelvic area and I even heard of a woman with endometriosis who's lung collapsed every time she had a period. Can endometriosis really spread to the lungs?

Answer:
Yes, while it is rare, endometriosis can grow in the lung. This is also known as thoracic endometriosis. There are two basic types of thoracic endometriosis. Thoracic endometriosis can be divided into pleural endometriosis (the lining of the lung) and parenchymal endometriosis (the lung itself). The majority of cases of pulmonary endometriosis occur in the pleura rather than the lung itself (about 5:1 - pleura:parenchyma).

PLEURAL ENDOMETRIOSIS:
The vast majority of patients with pleural endometriosis experience difficulty breathing (shortness of breath), pain, and pneumothorax (collapsed lung) or pleural effusion (water on the lung). Over 90% of cases are right sided. It is not uncommon to find small holes in the diaphragm. The majority of patients with pleural endometriosis also have pelvic endometriosis, raising the question if spread of the endometriosis is via the small holes in the diaphragm.

PARENCHYMAL ENDOMETRIOSIS:
Most patients with parenchymal endometriosis cough up blood but few have difficulty breathing or pain. Few of these patients have pelvic endometriosis but usually have a history of pelvic surgery or vaginal delivery. The theory is that the endometrial cells spread through the blood vessels as emboli.

TREATMENT OF THORACIC ENDOMETRIOSIS:
In the past diagnosis of thoracic endometriosis has been difficult and treatment often involved either medical suppression of the endometriosis (e.g. danazol or GnRH agonists) or surgery in the form of a thoracotomy (big incision between the ribs) and obliteration of the pleural space (in order to prevent the lung from collapsing) without actually diagnosing or removing the endometriosis. The patient's history plays a key role in the diagnosis of thoracic endometriosis. Traditionally a chest x-ray or ventilation/perfusion study (a study which looks at both the air flow and blood flow through the lung) have helped in the diagnosis of endometriosis. MRI's have now advanced to the point that they can help locate and diagnose endometriosis. Thoracoscopy (laparoscopy of the thorax/pleural space) can help diagnose and treat pleural endometriosis (greater than 80% of thoracic endometriosis). Normally, when a patient undergoes general anesthesia, a breathing tube is placed through her mouth and down the bronchus and placed on a ventilator during the surgery. This tube is removed as she wakes up. To perform a thoracoscopy, a special double lumen breathing tube is placed through the patient's mouth, with one tube in the right lung and one tube in the left lung. At rest a person can easily get all the air they need through one lung. The side which contains the endometriosis, lets say the right, is collapsed by blocking off the tube on that side and the patient is ventilated (breaths) through the open tube, the left lung in this case. The collapsed lung opens up the pleural space and the thorascope is introduced into the pleural space. The pleural cavity is inspected and any endometriosis, scarring or fibrosis is removed. The thorascope is then removed and the incision is closed and the lung is re-inflated. Laparoscopy should also be performed to look for endometriosis in the pelvis, abdominal cavity, diaphragm, etc.

Updatede October 29, 2005