mesothelioma
Meaning of mesothelioma: A cancer of the mesothelium, the thin lining around the lungs, abdomen or heart, strongly associated with past asbestos exposure.
Definition of mesothelioma
Mesothelioma is a cancer that arises in the mesothelium, the thin layer of tissue lining the chest cavity, abdominal cavity and the sac around the heart. It is strongly linked to inhaled asbestos fibers and typically appears decades after exposure. Because it begins in the lining surrounding an organ rather than in the organ itself, it is a distinct disease from lung cancer.
How asbestos causes it
Inhaled or swallowed asbestos fibers are too durable for the body to clear. They lodge in the mesothelial lining, where decades of persistent irritation and inflammation cause genetic damage in the surrounding cells. This is why the latency period is so long: the disease usually surfaces many years after the exposure that caused it, often after a person has retired from the work that involved it.
Where it occurs
| Type | Lining affected | Relative frequency |
|---|---|---|
| Pleural | Around the lungs | Most common |
| Peritoneal | Abdominal cavity | Less common |
| Pericardial | Sac around the heart | Rare |
| Tunica vaginalis | Lining around the testis | Very rare |
Why it is hard to diagnose early
Early symptoms are vague and shared with far more common conditions: breathlessness, chest or abdominal discomfort, fatigue, unexplained weight loss. Fluid collecting around the lung or in the abdomen is often the first objective sign. Imaging alone rarely settles the question, so diagnosis usually rests on tissue sampling and specialised staining, since mesothelioma can closely resemble other cancers under the microscope.
Terms often confused with it
- Lung cancer begins in lung tissue itself; mesothelioma begins in the lining around it.
- Asbestosis is scarring of lung tissue from asbestos, not a cancer.
- Pleural plaques are benign thickened patches marking past exposure, not tumors.
Used in a sentence
Imaging findings in the patient with a history of asbestos exposure raised concern for pleural mesothelioma.
Good to know
Mesothelioma is distinct from lung cancer, since it arises from the lining surrounding the lung rather than from lung tissue itself, even though both are associated with asbestos exposure.
Word origin
Where “mesothelioma” comes from
Formed from meso-, from Greek mesos, meaning middle, and thelium, referring to the epithelial lining tissue, combined with -oma, meaning tumor.