Mesothelioma is a cancer that begins in the mesothelium, the thin tissue surrounding certain organs and body cavities. It most commonly affects the pleura around the lungs and may also arise in the abdominal lining. Because the disease is uncommon and often develops decades after asbestos exposure, patients benefit from clear information and experienced care.
Key information
- Asbestos exposure is the major known risk factor for adult mesothelioma.
- Pleural mesothelioma affects tissue around the lungs; peritoneal mesothelioma affects the abdominal lining.
- Symptoms overlap with many more common conditions and cannot establish a diagnosis.
- Imaging helps identify abnormalities, but tissue examination is generally needed to confirm mesothelioma.
- Treatment depends on cancer location, stage, cell type, overall health and patient goals.
Understanding the disease
Mesothelioma is different from lung cancer. Pleural mesothelioma begins in the tissue around a lung, while lung cancer begins within lung tissue. Both may be associated with asbestos, and differentiating them can require expert pathology.
The main anatomical types are pleural and peritoneal mesothelioma. Much rarer forms can affect tissue around the heart or a testicle. Pathologists also describe tumor cells as epithelioid, sarcomatoid or biphasic.
Learn about mesothelioma types and cell types
Symptoms
Pleural disease may cause shortness of breath, chest discomfort, cough, fatigue or fluid around a lung. Peritoneal disease may cause abdominal swelling, pain, appetite changes, nausea, bowel changes or unexplained weight loss. These problems have many possible causes.
Contact a health professional about persistent, worsening or concerning symptoms. Severe breathing difficulty, fainting, new confusion, blue or gray lips, or intense chest pain may require emergency care.
Review possible mesothelioma symptoms
Diagnosis and staging
Evaluation may include medical and exposure histories, physical examination, imaging and procedures to collect fluid or tissue. A pathologist examines biopsy tissue and may use special laboratory stains to distinguish mesothelioma from other cancers.
Staging describes the extent of cancer and helps guide treatment. Pleural mesothelioma commonly uses a TNM framework that considers the tumor, lymph nodes and distant spread.
How mesothelioma is diagnosed Understand mesothelioma stages
Treatment
A treatment plan may involve surgery, systemic medicines such as chemotherapy or immunotherapy, radiation, procedures to manage fluid, supportive care or a clinical trial. Not every treatment is appropriate for every person.
Because mesothelioma is rare, consider asking whether a multidisciplinary team or center experienced with the disease should review the case. A second pathology or treatment opinion may confirm the plan or present alternatives.
Prognosis
Prognosis is an estimate, not a prediction of what will happen to one individual. Factors include cancer location and stage, cell type, whether surgery is feasible, performance status, heart and lung health, age and response to treatment. Population statistics cannot account for every individual difference or newer treatments.
Learn how prognosis is assessed
Asbestos exposure
Exposure may have occurred through work, military service, home renovation, consumer or industrial products, environmental sources, or fibers carried home by another worker. A long latency period means relevant events may have happened many years earlier.
Do not disturb suspected asbestos material to investigate an exposure. Use qualified inspectors and abatement professionals.
Learn where asbestos exposure happens
Practical next steps
- Request copies of pathology, imaging and treatment records.
- Write down questions before appointments and bring a support person if helpful.
- Ask about the exact type, cell type, stage and treatment goal.
- Consider an experienced second opinion.
- Start a safe written employment, military and household exposure history.
- Review insurance, leave, travel and caregiver needs.
- If seeking legal information, remember that deadlines vary by state.
Sources
- National Cancer Institute. Mesothelioma.
- National Cancer Institute. What Is Mesothelioma? Updated May 16, 2025.
- National Cancer Institute. Diagnosis and Prognosis Updated May 16, 2025.
- National Cancer Institute. Treatment for Mesothelioma Updated May 16, 2025.
- Agency for Toxic Substances and Disease Registry. Health Effects of Asbestos.
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