Endometriosis in the Lungs

Endometriosis tissue is most frequently observed in the pelvic region or on the ovaries. Occasionally, although uncommon, these lesions can also establish themselves in the lungs [1]. This occurrence may manifest through symptoms like chest pain, breathlessness, and coughing [2]. How exactly does this unintended tissue find its way into the lungs, and what potential complications can arise from this? Today, we embark on a journey to unravel these intriguing queries and more.

Thoracic Endometriosis Syndrome (TES)

Thoracic endometriosis encompasses the thoracic cavity and its adjacent regions. Within the spectrum of endometriosis, medical professionals categorize this variant as “endometriosis extragenitalis.” In this context, lesions materialize across diverse organs and tissues outside the uterus. Notably, this can encompass the bladder, ureter, and vagina. On rare occasions, endometriosis lesions extend to the lungs. If endometriosis-like tissue manifests in the pleura, diaphragm, or lung parenchyma, healthcare practitioners label it “thoracic endometriosis syndrome (TES).” To elucidate, the lung parenchyma is the essential respiratory tissue responsible for breathing.

Insight: The Mechanics of Lung Function

Endometriosis affecting the lungs can yield profound ramifications. To provide a backdrop for comprehending the significance of diagnosing and treating lung-endometriosis lesions, let’s delve into the mechanics of lung operation. Among the most fundamental organs, the lungs undertake the task of extracting oxygen from the air we breathe and distributing it throughout the body. This function is pivotal since cellular energy production hinges on ample oxygen availability. Nestled within the rib cage, the delicate lung organ resembles a tree, wherein the trachea mimics the tree trunk. Embracing this analogy, the two primary bronchi sprout like branches on either side. These bronchi bifurcate further into progressively smaller branches within the lungs—one on the left and one on the right of the trachea. Culminating these branches are the alveoli, tiny sac-like structures [3].

The process of breathing remains consistent [3]:

1. Inhalation: The chest expands as you inhale.
2. Oxygen-laden air journeys from the trachea via the bronchi to the alveoli.
3. The alveolar lining hosts fine blood vessels facilitating oxygen transfer into the bloodstream.
4. Oxygen disperses across the entire body, energizing every cell and corner.
5. Exhalation: The lungs contract as you exhale, expelling “used” air.

Good to know!

The alveoli shoulder not only the responsibility of oxygen uptake into the blood but also the reabsorption of carbon dioxide from the bloodstream. This intricate mechanism is termed gas exchange [3]. Effective lung function is pivotal to providing your body with adequate oxygen. Any disruption caused by endometriosis lesions can disrupt the delicate equilibrium within the lungs, potentially inducing distressing symptoms.

Lung-endometriosis: Recognizing Symptoms

Respiratory efficiency substantially impacts overall performance, and individuals grappling with lung conditions often experience a marked reduction in their quality of life. In the realm of lung-related issues, the emergence of endometriosis can trigger distressing symptoms and complications. Given the relative rarity of endometriosis within the lungs, those afflicted may not immediately attribute their symptoms to such lesions.

The ensuing symptoms are commonly associated with endometriosis in the lungs [1]:

• Chest pain
• Pneumothorax (accumulation of air in the chest)
• Hemothorax (accumulation of blood in the chest)
• Hemoptysis (expectoration of bloody secretions)
• Pain radiating toward the right shoulder

Distinctive Type: Catamenial Pneumothorax

Pneumothorax signifies the accumulation of air within the pleural space—the area nestled between the lung and the chest wall, enveloped by a thin fluid layer. This locale sustains a minor negative pressure, affixing the lung to the chest wall while allowing slight mobility during respiration. However, if air infiltrates this space, the lung loses its adhesion to the chest wall and collapses, bestowing pneumothorax its moniker—”lung collapse.”

Pneumothorax can arise from various triggers, including medical procedures or injuries, even without apparent provocation [4].

Catamenial pneumothorax stands as a unique manifestation intricately linked to endometriosis. Its hallmarks encompass characteristic complaints such as chest pain, breathlessness, and shoulder tension. Notably, these symptoms align temporally with the menstrual cycle, warranting its designation as “catamenial” or “menstrual” pneumothorax. Typically, these symptoms surface one to three days before the onset of menstruation. Intriguingly, the pivotal question revolves around the underlying causative factors.

Two scenarios outline the mechanisms through which air infiltrates the pleural space. The air might originate within the lung itself, particularly if endometriosis lesions reside on the lung. Alternatively, another avenue involves the passage of air from the uterus into the thoracic cavity. Even in the absence of endometriosis, air can traverse the vaginal route and traverse the fallopian tubes, entering the abdominal cavity. However, should endometriosis tissue compromise the diaphragm’s integrity, air can permeate into the pleural space [5, 6].

Catamenial lung collapse is intrinsically rare. Pneumothorax (lung collapse) is more frequently observed in young males than in females.

How Common is Catamenial Pneumothorax?

Catamenial pneumothorax may seem akin to a mythical unicorn within the realm of lung collapse, and on a broad scale, it is indeed rare. However, its consideration should remain paramount, particularly in the context of lung collapse among young women, as suggested by a specific study. Focusing solely on women of childbearing age with pneumothorax, endometriosis emerges as a notable cause. Within this subset, the incidence of catamenial pneumothorax has been reported to range from 7.3% to 36.7%. Admittedly, this variance encompasses a wide spectrum, underscoring that menstrual pneumothorax may not be as uncommon as initially presumed. Intriguingly, research indicates that individuals afflicted by catamenial pneumothorax tend to be relatively older than women with other forms of endometriosis. Notably, one study documented an average age of 35 years old [10]. Another study has contributed captivating insights [7]:

• In 89% of instances, endometriosis manifested at the diaphragm.
• Within 93% of cases, the right thoracic half bore the impact.
• 55% of cases with diaphragmatic endometriosis also featured pelvic endometriosis.
• Half of the affected patients had previously undergone surgical intervention for pelvic endometriosis.

Good to know!

The perplexing question arises: How does endometriosis tissue find its way into the lungs? A myriad of theories grapples with this enigma. A prevailing hypothesis suggests that these cells may journey through the peritoneum—a tissue lining the abdominal cavity. However, this notion falters in explaining instances of lung endometriosis in patients devoid of corresponding pelvic tissue. Consequently, contemporary research has veered away from this hypothesis. An emerging discourse ponders whether distinct strains of endometriosis cells might be orchestrating their migration to the lungs. Yet, this avenue of inquiry remains shrouded in uncertainty, necessitating further comprehensive investigation. [2].

Clinical Cases Illustrating Lung Endometriosis

Encounters with patients exhibiting endometriosis in the lungs are rare for most medical professionals. Thus, it becomes imperative to disseminate the existing evidence on this condition. Allow me to acquaint you with a couple of documented cases that shed light on the possible manifestations of lung endometriosis. These instances offer insight into the diverse ways in which this condition can manifest.

A Clinical Case from Greece

A Clinical Case from China

In a similar narrative, a 29-year-old woman’s health ordeal brought her to medical attention. She experienced recurring episodes of chest pain and bouts of coughing. Initially, a misdiagnosis of tuberculosis led to a course of antibiotic treatment.

Initially, her condition appeared to improve, but the symptoms resurged. Taking matters into her own hands, she ceased the antibiotic regimen and sought consultation with a pulmonary specialist. During discussions with the medical professional, the patient revealed a critical piece of information—her symptoms occurred cyclically, once a month. This insight proved pivotal. Pursuing a comprehensive evaluation, the woman underwent a computed tomography (CT) scan while she was menstruating. The CT images illuminated an inflammatory response and the presence of a nodule within her lung. A bronchoscopy procedure was performed, facilitating the removal of tissue for laboratory analysis. Subsequently, the diagnosis of endometriosis in the lung was confirmed. A surgical intervention followed to excise the endometriosis lesions [9].

Diagnosing Endometriosis in the Lungs

The process of diagnosing endometriosis in the lungs often commences with a thorough medical history discussion between the patient and their physician. Insight into the timing of symptoms is particularly valuable—symptoms that coincide with menstruation might point to lung endometriosis. Additionally, it’s pertinent to inquire about any prior endometriosis diagnoses and treatments, as this can offer important context. To substantiate suspicions and rule out other potential conditions, diagnostic imaging techniques play a pivotal role. Magnetic resonance imaging (MRI) and computed tomography (CT) scans are especially instrumental in visualizing lung abnormalities. These imaging modalities can unveil the presence of nodules or manifest changes in the form of shading or infiltrations. Drawing from the aforementioned case from China, a bronchoscopy procedure may be conducted to procure tissue samples, which are subsequently analyzed in a laboratory. Upon confirmation of the diagnosis, targeted therapeutic interventions can be devised to manage and alleviate the condition’s impact.

Treatment of Endometriosis in the Lungs

Effective management of endometriosis in the lungs is crucial to alleviate symptoms and mitigate potential complications. The therapeutic approach involves a combination of drug therapy and, if necessary, surgical intervention. The initial step in treatment, as outlined by the guideline program of the German Society for Gynecology and Obstetrics (DGGG) often involves drug therapy.

Specifically, medications that regulate estrogen levels are commonly employed. Progestogen preparations or Gonadotropin-Releasing Hormone (GnRH) agonists are examples of such treatments. In cases where drug therapy fails to yield desired outcomes, surgical intervention might be considered. A laparoscopic-thoracoscopic approach, which involves examining both the thoracic and abdominal cavities, has shown favorable results. This comprehensive exploration ensures the detection of all endometriosis lesions in the region. Following surgery, estrogen suppression through hormone suppression is recommended to lower the risk of recurrence, as stated by the guideline program of the German Society of Gynecology and Obstetrics. By implementing this combined therapeutic strategy, patients can experience symptom relief and a reduced likelihood of recurrent symptoms [1, 10, 11].

Good to know!

In both diagnosis and treatment, a thorough gynecological evaluation is essential. Additionally, carefully analyzing the female reproductive cycle and closely observing any symptoms originating from the lung region are crucial steps [12].

In a Nutshell

Endometriosis affecting the lungs is a rare occurrence. The symptoms it triggers often lack specificity, which can lead to them not being immediately linked to endometriosis. Manifestations may encompass chest pain, the accumulation of blood in the chest (hemothorax), and pain extending to the shoulder. A unique manifestation, catamenial pneumothorax or menstrual pneumothorax, is closely associated with endometriosis. This condition involves the buildup of air in the chest, resulting in symptoms like breathlessness.

Endometriosis can be found in various lung areas, including the pleura, diaphragm, and lung parenchyma—the vital tissue for breathing. Clinicians term this phenomenon “thoracic endometriosis syndrome (TES).” Despite ongoing research, the precise reasons behind the settlement of endometriosis tissue in the lungs remain not fully elucidated. Diagnosing this condition primarily involves imaging techniques and bronchoscopy with accompanying biopsies. When a confirmed diagnosis of endometriosis in the lungs is established, treatment options include conservative measures employing medication. This approach targets the reduction of estrogen levels, as estrogen fosters endometriosis growth. If medication fails to yield the desired outcomes, surgical intervention becomes a consideration. In such cases, it is crucial to integrate hormone suppression through medication to mitigate the risk of recurrence.