Pleural Effusion & Mesothelioma

Expert Fact Checked

This page was medically reviewed by James Stevenson, M.D.. For information on our content creation and review process read our editorial guidelines. If you notice an error or have comments or questions on our content please contact us.

James Stevenson, M.D. Thoracic Medical Oncologist

A pleural effusion is a buildup of excess fluid between the lining of the lungs and chest cavity. Pleural effusion may be a symptom of mesothelioma, lung cancer or other diseases. It can cause breathlessness, chest pain and dry cough. Pleural effusion can be treated to relieve patients’ symptoms.

01. Defining Pleural Effusion

What Is Pleural Effusion?

A pleural effusion occurs when excess fluid collects between the membranes that line the lungs and chest wall. This lining is called the pleura. The area between the pleura is the pleural space.

In the United States, malignant pleural effusion is responsible for more than 125,000 hospital admissions yearly.

The body normally produces a small amount of fluid between the pleura to facilitate breathing. A pleural effusion occurs when there is more fluid than normal. The excess of fluid may prevent the lungs from fully expanding. As a result, patients may have a hard time breathing.

Pleural effusion may be caused by irritation, inflammation or infection of the pleura. These issues can stem from a variety of conditions, including malignant mesothelioma.

02. Connection to Mesothelioma

The Relationship Between Mesothelioma and Pleural Effusions

Pleural effusion is a common symptom of malignant pleural mesothelioma. Pleural mesothelioma develops in the lining of the lungs after asbestos exposure. The asbestos fibers can cause inflammation in the lungs, which may lead to pleural effusion.

Researchers from the Moffitt Cancer Center have reported between 80– 95% of pleural mesothelioma patients have pleural effusions.

Pleural effusion becomes less common as pleural mesothelioma progresses. This is due to medical intervention or tumor growth. If a tumor engulfs the pleural space, fluid buildup is inhibited. As a result, existing pleural effusions may resolve.

Understanding Common Mesothelioma Symptoms: Pleural Effusion vs. Pleural Thickening

Pleural effusion and pleural thickening are both symptoms of pleural mesothelioma. These symptoms may occur simultaneously but are separate conditions.

Pleural thickening is the progressive buildup of scar tissue on the pleura. In some cases, pleural thickening may follow pleural effusion.

03. Pleural Effusion Causes

What Causes Pleural Effusions?

Pleural effusions are caused by various underlying diseases. The most common causes are heart disease, cancer, pneumonia and pulmonary embolism. Other factors and behaviors can increase a patient’s risk of pleural effusion.

Pleural Effusion Risk Factors
  • Drinking alcohol
  • History of asbestos exposure
  • History of high blood pressure
  • Smoking

Pleural effusions may be malignant or benign, depending on the cause:

  • Malignant pleural effusion is caused by cancer.
  • Benign pleural effusion is caused by an illness that is not cancer.

The distinction is important for prognosis and treatment.

Researchers estimate pleural effusion may develop in nearly 50% of all metastatic cancer patients. Malignant pleural effusion is a common symptom of lung cancer and pleural mesothelioma. It may also be a sign of other asbestos cancer types.

Asbestos-Related Pleural Effusion

Exposure to asbestos can increase a person’s risk of developing pleural effusion. Inhaled or ingested asbestos fibers can become embedded in the lining of the lungs, or pleura, and cause inflammation. This inflammation may cause nearby blood vessels to leak fluid into the pleural space.

In rare cases, asbestos exposure can cause benign asbestos pleural effusion (BAPE). BAPE is diagnosed when a patient had previous asbestos exposure and no other causes of pleural effusion are present. Patients diagnosed with BAPE do not have mesothelioma cancer, but may develop it in the future.

04. Signs & Symptoms

What Are the Signs and Symptoms of Pleural Effusion?

Pleural effusion is often a sign of another condition. However, the fluid buildup may also cause various symptoms.

For some pleural mesothelioma patients, pleural effusions may be asymptomatic. Other mesothelioma patients may experience a variety of symptoms.

Signs of Pleural Effusion May Include:

  • Chest pain
  • Dry cough
  • Dyspnea (shortness of breath)
  • Fatigue
  • Fever
  • Orthopnea (inability to breathe easily unless sitting up or standing)

Symptoms can range from mild to severe based on the amount of fluid in the pleural space. The greater the amount of fluid, the more noticeable symptoms may become.

05. Diagnosis

Diagnosing Pleural Effusion

After a patient presents with symptoms, doctors will conduct a physical examination. Doctors also commonly use imaging scans, such as a chest X-ray, CT scan, or ultrasound, to diagnose a pleural effusion.

Pleural effusions may be a sign of a serious disease. If the cause of the pleural effusion remains undiagnosed, further testing may be required.

How Is the Underlying Cause of Pleural Effusion Diagnosed?

To determine the cause of pleural effusion, doctors may prescribe additional procedures. For instance, doctors may take a biopsy (a sample of the pleural fluid). They will then analyze the pleural fluid to help determine the underlying cause of the pleural effusion.

Pleural fluid can be categorized as exudative or transudative. The distinction is based on protein concentration in the pleural fluid. Exudative effusions typically are more protein-rich than transudative effusions and more likely to indicate mesothelioma.

Exudative Pleural Effusion

  • Protein-rich
  • Common causes: inflammation of the lung from tumor growth, cancer, inflammatory disease
  • Most common type for mesothelioma patients

Transudative Pleural Effusion

  • Protein-poor or watery
  • Common causes: fluid leakage into the pleural cavity, heart failure, cirrhosis, pulmonary embolism
  • Less likely in pleural mesothelioma cases

This classification may help doctors diagnose the cause of pleural effusion.

Early Detection of Pleural Effusion Can Help Mesothelioma Patients

Early detection of pleural effusion may also lead to an early mesothelioma diagnosis.

Some patients with benign pleural effusion and a history of asbestos exposure may later develop malignant pleural mesothelioma. In these cases, doctors can continue to monitor the patient for signs of mesothelioma. This can aid early diagnosis if the patient later develops the cancer.

Early diagnosis of mesothelioma is one of the best ways to improve a patient’s prognosis. An individual’s mesothelioma prognosis also depends on cell type, as well as the patient’s age and overall health, among other factors.

06. Common Treatments

Common Pleural Effusion Treatments

Pleural effusion is common, and there are several treatments available. These treatments will not cure the patient’s underlying condition, but they may relieve symptoms.

In cases of minor pleural effusions, the patient may not need any treatment. When doctors know the cause of the effusion, such as pleural mesothelioma, they will treat the underlying cause.

Doctors can treat pleural effusions in mesothelioma patients with short- or long-term solutions. Depending on the patient’s case, they may receive palliative treatments to manage the pleural effusion.

Some patients may also undergo mesothelioma treatments, such as chemotherapy, to treat the cancer itself. Comprehensive treatment plans may improve a patient’s life expectancy.

Short-Term Symptom Relief for Patients With Pleural Effusions

Short-term pleural effusion treatments entail one-time drainage of excess fluid. Short-term pleural effusion treatment options include:

  • Thoracentesis (Pleurocentesis): Doctors use a long and hollow needle to remove fluid from within the pleural cavity. Reducing fluid volume provides the patient with symptom relief.

Long-Term Symptom Relief for Patients With Pleural Effusions

Long-term pleural effusion treatments may allow repeated fluid drainage or prevent fluid buildup. Long-term pleural effusion treatment options include:

  • Pleural drain or pleural catheter: A doctor places a catheter inside the pleural cavity to drain fluid. The catheter remains in place as a long-term solution. The patient or a healthcare professional can open the catheter as necessary to remove fluid from the pleural space.
  • Pleurectomy/decortication: In rare cases, mesothelioma patients with pleural effusion may undergo a pleurectomy/decortication (P/D). The surgery involves removing pleural tumors and the pleural lining.
  • Pleurodesis: This surgical procedure closes the pleural space to prevent fluid buildup. Doctors drain existing fluid through a hollow tube inserted in the chest wall. They also insert medication through a chest tube to mitigate the patient’s future risk of pleural effusion. Doctors typically recommend a pleurodesis if the effusion is likely to recur.
  • Pleuroperitoneal shunt: Doctors place a tube in the abdomen to connect the pleural space with the peritoneal cavity. The patient can manually pump fluid out of the pleural space and into the peritoneum. The fluid can be absorbed by the body in the peritoneum.
  • Video-assisted thoracoscopic surgery (VATS): VATS is often used for malignant pleural effusions. The procedure is minimally invasive and involves surgeons using cameras to guide the drainage of pleural fluid.
  • Thoracotomy: A thoracotomy is a more invasive procedure than VATS. Doctors may recommend the procedure if patients have an infection within the pleural cavity. Patients may need chest tubes for up to two weeks following a thoracotomy.

These treatments can provide symptom relief for patients with pleural effusion, including those with mesothelioma. Depending on the patient’s case, they may undergo other forms of treatment for the cancer.

Early detection and treatment of pleural effusions, and the underlying conditions, may improve patient survival. Mesothelioma patients with pleural effusion may improve their symptoms and quality of life through treatment.