Pleural mesothelioma is the most common form of mesothelioma, accounting for roughly 75-80% of all cases. It develops in the pleura — the thin membrane lining the lungs and chest cavity — after asbestos fibers reach and irritate that lining over decades.

Cause

Pleural mesothelioma is caused by inhaling asbestos fibers. The fibers travel to the pleura, where they cause chronic inflammation and cellular damage that can, 20 to 50 years later, develop into cancer. Workers in insulation, construction, shipbuilding, the Navy, power generation, and industrial trades — and their family members exposed secondhand — are among the most affected.

Symptoms

  • Shortness of breath (often from fluid buildup, or pleural effusion)
  • Chest pain or tightness
  • Persistent cough
  • Fatigue and unexplained weight loss
  • Low-grade fever or night sweats

See the full symptoms guide for detail.

Diagnosis

Diagnosis typically involves imaging (chest X-ray, CT, PET, or MRI), analysis of pleural fluid, and a biopsy to confirm the cancer and determine its cell type (epithelioid, sarcomatoid, or biphasic), which affects treatment and prognosis.

Treatment

Treatment depends on the stage, cell type, and the patient’s health, and is usually multimodal:

  • Surgery (such as pleurectomy/decortication or extrapleural pneumonectomy) for eligible patients
  • Chemotherapy
  • Radiation therapy
  • Immunotherapy, which has become an important option in recent years
  • Clinical trials offering access to emerging treatments

A multidisciplinary team — thoracic surgeons, oncologists, and pulmonologists — guides treatment planning.

Why It Is Usually Found Late

Pleural mesothelioma has a latency of roughly twenty to fifty years between asbestos exposure and diagnosis. By the time it produces symptoms, those symptoms — breathlessness, chest discomfort, a persistent dry cough, fatigue — are indistinguishable from several far more common conditions. It is routinely treated first as pneumonia, pleurisy or a COPD exacerbation.

The single most useful thing a patient can contribute is the exposure history. It changes what the differential looks like from the first appointment, and it is the reason a trade history going back fifty years belongs in a medical conversation and not only a legal one.

Managing Pleural Effusion

Fluid building up between the lung and chest wall is often the first thing that brings someone in, and it is treated as its own problem alongside the cancer. Thoracentesis drains it with a needle and relieves breathlessness quickly, but fluid usually returns. Pleurodesis introduces a agent — commonly talc — to seal the pleural space so fluid cannot reaccumulate. An indwelling pleural catheter lets a patient drain at home instead, and is often preferred when the lung cannot fully re-expand.

These are comfort and function measures rather than cancer treatment, and they run alongside disease-directed therapy rather than instead of it. Getting breathlessness under control early tends to matter more to daily life than any other single intervention.

The Surgical Debate

Two operations are used, and which is appropriate is genuinely contested among specialists:

  • Extrapleural pneumonectomy (EPP) removes the pleura, the entire lung on that side, part of the diaphragm and the pericardium. It is the more radical option, carries substantial risk, and requires a patient with good function in the remaining lung.
  • Pleurectomy/decortication (P/D) strips the pleura and visible tumour but spares the lung. Recovery is generally better tolerated, and many centres have moved toward it as the default where either is possible.

There is no settled answer, and recommendations differ by centre — which is itself a reason to get an opinion from a programme that performs both regularly.

Systemic Treatment

For patients who are not surgical candidates — which is most — treatment is systemic. Nivolumab plus ipilimumab, two immunotherapy drugs used together, was approved by the FDA in 2020 as a first-line option for unresectable pleural mesothelioma after the Phase 3 CheckMate 743 trial showed longer median overall survival than chemotherapy alone. Pemetrexed with a platinum agent remains a standard chemotherapy backbone, sometimes with an anti-angiogenic drug added.

Which is appropriate depends heavily on cell type, and the benefit of immunotherapy over chemotherapy has been most pronounced in non-epithelioid disease — one of several reasons the pathology report drives the treatment conversation.

Prognosis

Prognosis varies widely by stage, cell type, and treatment. See the life expectancy and prognosis guide and stages guide for more.

If you were diagnosed with pleural mesothelioma and were exposed to asbestos at work, in the military, or in a building, you may have a legal claim.

This information is educational, drawn from sources such as the American Cancer Society and National Cancer Institute, and is not medical advice. Consult your own physician about diagnosis and treatment.