Pleural-based cancers are malignancies that develop in the thin, double layer of tissue that surrounds the lungs. Pleural tumors may arise in both lung cancer and mesothelioma. Cancers of the pleura cause uncomfortable symptoms and are difficult to treat.
Metastatic Pleural Lung Cancer
The pleura are the two thin layers of tissue surrounding the lungs. Fluid between these layers provides lubrication and prevents friction and pain as the lungs expand and contract. Most organs in the body are surrounded by this type of tissue, called mesothelium.
Cancer of the pleura can be the result of metastatic lung cancer. Metastasis is the process of cancer cells moving from the original tumor to other tissues in the body.
Alternatively, it can also happen when cancer is isolated in the pleural space. Usually, metastasis occurs in the later stages of cancer when it is difficult to treat and the prognosis is poor.[1]
With lung cancer, the pleural tissue is a common area affected by metastasis. Cancer cells from primary tumors migrate to the pleura through the bloodstream or spread through the lymphatic system.
Cancer cells may also transfer to the pleura through simple contact, as the lungs press directly against this tissue. Once in the pleura, cancer cells may develop into one or multiple tumors or vice versa.
Pleural Effusions
Cancer in the pleura may or may not cause symptoms. The more advanced the cancer, the more likely it is to produce noticeable symptoms. A pleural effusion is an abnormal fluid buildup between the pleural layers.
This buildup can cause chest pain, especially when breathing deeply, shortness of breath, and coughing.[2] Other potential symptoms of pleural tumors include general discomfort, fatigue, and unintended weight loss.
Mesothelioma
Less common than lung cancer, mesothelioma is a primary cancer of the pleural tissue. It is strongly associated with asbestos exposure. Most people with this cancer encountered asbestos in the workplace and only developed symptoms decades later.
Diagnosing Pleural Based Disease
An accurate diagnosis is essential as this helps provide the best treatment recommendations; however, diagnosis can be difficult. Diagnostic steps include:[3][4]
- Imaging scans, such as X-rays, MRIs, and CT scans, help doctors determine the locations of tumors or fluid.
- A thoracentesis removes fluid to look for cancer cells. A needle is inserted to draw a fluid sample from the pleural space.
- A pathologist examines the sample under a microscope to look for specific chemical markers.
- If the thoracentesis is inconclusive, a doctor may use CT-guided biopsies of the chest wall lesions.
- If neither allows for a firm diagnosis, they will consider an open surgical pleural biopsy. This is invasive and risky, but obtaining a correct diagnosis is paramount.
Misdiagnosis and Mesothelioma
Cases of mesothelioma are often initially misdiagnosed because they are so rare. Doctors might diagnose lung cancer because it is more common than mesothelioma. Even if there are tumors in the pleura and the lungs, mesothelioma is a possibility. Lung tumors may be metastatic tumors.[4]
Pathologists and oncologists experienced in mesothelioma are better equipped to distinguish mesothelioma from lung cancer. Mesothelioma is aggressive and spreads quickly; therefore, misdiagnosis can shorten a patient’s life by delaying important treatment. Specific treatment depends on the type of primary tumor.
Treating Pleural Lung Cancer
If pleural tumors are genuinely caused by metastatic lung cancer, treatment options include systemic therapy with chemotherapy and sometimes targeted or immunotherapy.
Metastasis is an indication that the cancer is advanced, making treatment more difficult. Surgical removal of the tumors is invasive and not always possible; however, there may be exceptions depending on the patient’s overall health.[5]
Chemotherapy or radiation therapy may shrink primary tumors in the lungs and extend life expectancy; otherwise, treatment largely focuses on reducing symptoms to increase patient comfort.
This usually involves managing pleural effusion, which can be painful and limiting. Regular thoracentesis to remove fluid is a standard treatment option. In some cases, a catheter may be installed to drain the fluid regularly.
Lung cancer in the pleura alone is considered metastatic lung cancer. It is not uncommon to misdiagnose this cancer as mesothelioma, but it can be avoided with the right experts on hand.
If you have symptoms of pleural tumors or have been diagnosed with pleural lung cancer, it is worth seeking the opinion of a mesothelioma specialist. This is especially important if you suspect you have been exposed to asbestos in the past. If you are diagnosed with mesothelioma, consider letting an expert asbestos lawyer help you make a case for compensation for medical bills.
