This glossary provides plain-language definitions of 81+ terms commonly used in mesothelioma, asbestos, and legal contexts. Whether you are a patient, family member, medical professional, journalist, or researcher, these definitions are designed to clarify specialized terminology from medical diagnosis to legal procedure.
A
- Abatement
- The professional removal, encapsulation, or enclosure of asbestos-containing materials from a building or structure, performed by licensed contractors following EPA and OSHA protocols.
- Actinolite
- A type of amphibole asbestos, primarily found as a contaminant in other materials. Classified as a carcinogen.
- Adenocarcinoma
- A type of lung cancer that can be caused by asbestos exposure. Distinct from mesothelioma but sometimes co-occurs in asbestos-exposed patients.
- Amosite
- Brown asbestos, the second most commonly used type, primarily in insulation products, ceiling tiles, and cement products.
- Amphibole
- A family of asbestos minerals including amosite, crocidolite, tremolite, anthophyllite, and actinolite. Amphibole fibers are generally considered more dangerous than chrysotile.
- Anthophyllite
- A rare type of amphibole asbestos, primarily found as a contaminant in industrial products.
- Asbestos
- A group of six naturally occurring silicate minerals composed of microscopic fibers, widely used in the 20th century for fire resistance and insulation. Known cause of mesothelioma, lung cancer, asbestosis, and other diseases.
- Asbestosis
- A progressive, non-malignant scarring of the lungs caused by asbestos fiber accumulation. Causes shortness of breath and can be fatal. Distinct from cancer.
- Ascites
- Fluid buildup in the abdominal cavity, a common symptom of peritoneal mesothelioma.
B
- Bankruptcy Trust
- A financial trust established by an asbestos company that declared bankruptcy, required by federal law to compensate current and future asbestos disease victims. Over 60 active trusts hold more than $30 billion.
- Biopsy
- The removal of a tissue sample for laboratory examination. A biopsy is required to definitively diagnose mesothelioma.
- Biphasic Mesothelioma
- A cell type containing both epithelioid and sarcomatoid cells. Accounts for 20-30% of mesothelioma diagnoses. Prognosis depends on the ratio of cell types.
C
- CAR-T Cell Therapy
- An emerging immunotherapy approach where a patient's T cells are modified to attack cancer cells. Currently being studied in clinical trials for mesothelioma.
- Carboplatin
- A chemotherapy drug used as an alternative to cisplatin in mesothelioma treatment, particularly when cisplatin is not tolerated.
- Chemotherapy
- Treatment using drugs that kill cancer cells. The standard first-line mesothelioma regimen is pemetrexed combined with cisplatin or carboplatin.
- Chrysotile
- White asbestos, the most commonly used type, accounting for about 95% of commercial asbestos use in the United States. Banned by EPA in 2024.
- Cisplatin
- A platinum-based chemotherapy drug used in the standard first-line treatment for mesothelioma, combined with pemetrexed.
- Clinical Trial
- A research study testing new treatments, drug combinations, or approaches. Clinical trials are free to participants and provide access to emerging mesothelioma treatments.
- Contingency Fee
- A fee arrangement where an attorney is paid only if the case results in a settlement or verdict. The attorney receives a percentage of the recovery. Mesothelioma attorneys typically work on contingency.
- Crocidolite
- Blue asbestos, considered the most dangerous type due to its thin fiber structure that makes it particularly likely to cause mesothelioma.
- Cytoreductive Surgery
- Surgery that removes all visible tumor from the abdominal cavity. Typically combined with HIPEC for peritoneal mesothelioma treatment.
D
- Deposition
- Sworn testimony given outside of court during the discovery phase of a lawsuit. Mesothelioma patients often give depositions from home via video.
- DIC (Dependency and Indemnity Compensation)
- Monthly VA benefits paid to surviving spouses and dependents of veterans who died from service-connected conditions, including mesothelioma.
- Discovery Rule
- A legal principle stating that the statute of limitations begins when the patient is diagnosed (or reasonably should have been diagnosed), not when the exposure occurred. Critical for asbestos cases given the 20-50 year latency period.
- Discovery (legal)
- The pre-trial phase where both sides exchange evidence, including medical records, work history, and expert reports. Typically takes 3-6 months.
E
- EPP (Extrapleural Pneumonectomy)
- An aggressive surgery that removes the entire affected lung, pleura, diaphragm, and pericardium in pleural mesothelioma patients. Now less commonly used than P/D.
- Epithelioid Mesothelioma
- The most common mesothelioma cell type (50-70% of cases) with the best prognosis and most responsive to treatment.
- EPA (Environmental Protection Agency)
- The federal agency responsible for regulating asbestos. Finalized a comprehensive ban on chrysotile asbestos in 2024.
F
- Fibrosis
- Scarring of tissue. Asbestosis is a form of pulmonary fibrosis caused by asbestos fiber accumulation in the lungs.
- Friable
- Easily crumbled or reduced to powder. Friable asbestos-containing materials pose the greatest exposure risk because they release fibers readily.
H
- HIPEC (Hyperthermic Intraperitoneal Chemotherapy)
- Heated chemotherapy applied directly to the abdominal cavity during surgery for peritoneal mesothelioma. Has dramatically improved outcomes, with 5-year survival rates up to 50-60%.
- Histology
- The study of tissue structure under a microscope. Used to determine mesothelioma cell type (epithelioid, sarcomatoid, or biphasic).
I
- Immunohistochemistry
- A laboratory technique used in pathology to distinguish mesothelioma from other cancers with similar appearance.
- Immunotherapy
- Treatment that uses the body's immune system to fight cancer. The FDA-approved regimen for mesothelioma is nivolumab + ipilimumab, approved October 2020.
- IMRT (Intensity-Modulated Radiation Therapy)
- A radiation technique that delivers precisely targeted doses to cancer cells while minimizing damage to surrounding tissue. Used in mesothelioma treatment.
- Ipilimumab (Yervoy)
- An immunotherapy drug (checkpoint inhibitor) used in combination with nivolumab as FDA-approved first-line treatment for unresectable pleural mesothelioma.
L
- Latency Period
- The time between initial asbestos exposure and the appearance of symptoms or disease. For mesothelioma, this period is typically 20-50 years, averaging 30-40 years.
- Lawsuit
- A civil legal action filed in court seeking compensation for injuries. Mesothelioma lawsuits can be filed against companies that manufactured, distributed, or used asbestos-containing products.
M
- Madison County, Illinois
- One of the most active asbestos litigation jurisdictions in the United States. Experienced asbestos judges and juries handle thousands of cases.
- Mesothelioma
- A rare, aggressive cancer caused exclusively by asbestos exposure. Develops in the mesothelial lining of the lungs, abdomen, heart, or testicles. Approximately 3,000 U.S. diagnoses per year.
- Mesothelin
- A protein biomarker used to support mesothelioma diagnosis and monitor treatment response. Elevated levels (measured as SMRP) are found in many pleural mesothelioma patients.
- Mesothelium
- The thin tissue membrane lining internal body cavities and covering most internal organs. The tissue where mesothelioma develops.
- Metastasis
- The spread of cancer from the original site to distant organs or tissues. Stage IV mesothelioma has metastasized to distant organs.
- Multimodal Treatment
- A treatment approach combining two or more therapies — typically surgery, chemotherapy, radiation, and/or immunotherapy. The most effective strategy for mesothelioma.
N
- Nivolumab (Opdivo)
- An immunotherapy drug (checkpoint inhibitor) used in combination with ipilimumab as FDA-approved first-line treatment for unresectable pleural mesothelioma.
- NVLAP
- National Voluntary Laboratory Accreditation Program. Laboratories that analyze asbestos samples must be NVLAP-accredited.
O
- OSHA (Occupational Safety and Health Administration)
- The federal agency responsible for workplace safety standards, including asbestos exposure limits.
P
- P/D (Pleurectomy/Decortication)
- A lung-sparing surgery that removes the diseased pleura and visible tumor while preserving the lung. Increasingly preferred over EPP for pleural mesothelioma.
- Pathology
- The branch of medicine that examines tissue samples to diagnose disease. Mesothelioma diagnosis requires pathology confirmation by an experienced pathologist.
- Pemetrexed (Alimta)
- A chemotherapy drug that is the standard first-line treatment for mesothelioma, typically combined with cisplatin or carboplatin. FDA-approved for mesothelioma in 2004.
- Pericardial Mesothelioma
- Mesothelioma that develops in the pericardium (lining of the heart). Extremely rare, accounting for less than 1% of cases.
- Pericardium
- The thin membrane surrounding the heart. Can be affected by pericardial mesothelioma.
- Peritoneal Mesothelioma
- Mesothelioma that develops in the peritoneum (lining of the abdomen). Accounts for approximately 20% of cases. HIPEC treatment has significantly improved outcomes.
- Peritoneum
- The membrane lining the abdominal cavity. The tissue affected by peritoneal mesothelioma.
- PET Scan
- Positron emission tomography scan. Uses radioactive tracers to identify metabolically active cancer cells and determine if mesothelioma has spread.
- Pleura
- The thin membrane lining the lungs and chest cavity. The tissue affected by pleural mesothelioma.
- Pleural Effusion
- Fluid buildup between the lung and chest wall. A common symptom of pleural mesothelioma.
- Pleural Mesothelioma
- Mesothelioma that develops in the pleura (lining of the lungs). The most common type, accounting for approximately 75% of cases.
- Pleural Plaques
- Localized scarring on the pleura caused by asbestos exposure. Non-malignant but indicates exposure and can support legal claims.
- PLM (Polarized Light Microscopy)
- The primary laboratory technique used to identify and quantify asbestos in bulk material samples.
R
- Radiation Therapy
- Treatment using high-energy radiation to kill cancer cells. Often used as adjuvant treatment after mesothelioma surgery or for palliative symptom relief.
S
- Sarcomatoid Mesothelioma
- The rarest and most aggressive cell type (10-20% of cases). More resistant to treatment with the poorest prognosis. However, immunotherapy has shown promise for sarcomatoid patients.
- Secondary Exposure
- Also called take-home or paraoccupational exposure. Occurs when asbestos fibers are carried home on a worker's clothing and inhaled by family members. Has caused mesothelioma in many spouses and children of asbestos workers.
- SEER (Surveillance, Epidemiology, and End Results)
- The National Cancer Institute's cancer statistics program, providing authoritative data on cancer incidence, survival, and outcomes.
- Settlement
- An agreement between parties to resolve a lawsuit without going to trial. Approximately 90-95% of mesothelioma cases settle.
- SMRP (Soluble Mesothelin-Related Peptides)
- A blood biomarker elevated in many pleural mesothelioma patients. Supports diagnosis and monitors treatment response.
- Staging
- The process of determining how far cancer has spread. Mesothelioma uses the TNM system (Tumor, Node, Metastasis) with stages I-IV.
- Statute of Limitations
- The legal deadline for filing a lawsuit. For asbestos cases, most states use the discovery rule — the clock starts at diagnosis, not exposure. Deadlines vary by state (1-5 years).
- Synergistic Effect
- The combined effect of two factors that is greater than the sum of their individual effects. Asbestos + smoking has a synergistic effect on lung cancer risk (50-90x increased risk vs. 5x for asbestos alone).
T
- Testicular Mesothelioma
- The rarest form of mesothelioma (less than 1% of cases), developing in the tunica vaginalis. Despite being the rarest, has the most favorable prognosis.
- TEM (Transmission Electron Microscopy)
- A highly sensitive laboratory technique used to identify asbestos fibers, especially for air samples and trace contamination.
- TNM Staging
- A cancer staging system that classifies tumor size (T), lymph node involvement (N), and metastasis (M). Used to stage pleural mesothelioma.
- Transite
- Asbestos-cement products used for pipes, sheets, panels, and roofing. Common in industrial and commercial construction.
- Tremolite
- A type of amphibole asbestos, commonly found as a contaminant in vermiculite (Zonolite) and some talc deposits.
- Trust Distribution Process (TDP)
- The procedure by which asbestos bankruptcy trusts evaluate and pay claims. Typically offers both expedited review (fixed values) and individual review (higher potential values).
- Tunica Vaginalis
- The membrane lining the testes. The site of testicular mesothelioma.
V
- VA Benefits
- Department of Veterans Affairs compensation for service-connected conditions including mesothelioma. Mesothelioma is typically rated at 100% disability. Can be received alongside legal claims.
- Verdict
- A jury's decision at the end of a trial. Mesothelioma jury verdicts can be higher than settlements due to punitive damages but are less predictable.
- Vermiculite
- A mineral that, when mined at the W.R. Grace Libby, Montana mine, was contaminated with tremolite asbestos. Sold as Zonolite attic insulation in 35 million American homes.
W
- Wrongful Death
- A lawsuit filed by surviving family members when a person dies due to another party's negligence or misconduct. Statute of limitations typically starts at date of death.
Z
- Zonolite
- A brand of vermiculite attic insulation sold by W.R. Grace, contaminated with tremolite asbestos from the Libby, Montana mine. Installed in an estimated 35 million American homes.