Mesothelioma :: Glossary

asbestos (as-BES-tus)
A natural material that is made up of tiny fibers. The fibers can cause cancer.

peritoneum (PAIR-ih-toe-NEE-um)
The tissue that lines the abdominal wall and covers most of the organs in the abdomen.

pleura (PLOOR-a)
A thin layer of tissue covering the lungs and lining the interior wall of the chest cavity. It protects and cushions the lungs. This tissue secretes a small amount of fluid that acts as a lubricant, allowing the lungs to move smoothly in the chest cavity while breathing.

median
A statistics term. The middle value in a set of measurements.

mesoderm
the middle of the three germ layers, or masses of cells (lying between the ectoderm and endoderm), which appears early in the development of an animal embryo. In vertebrates it subsequently gives rise to muscle, connective tissue, cartilage, bone, notochord, blood, bone marrow, lymphoid tissue, and to the epithelia (surface, or lining, tissues) of blood vessels, lymphatic…

malignant mesothelioma
A rare type of cancer in which malignant cells are found in the sac lining the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.

mesothelioma
A benign (noncancerous) or malignant (cancerous) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the air increases the risk of developing malignant mesothelioma.

mesothelium
membranous tissue which originated in the embryonic mesoderm and covers internal and external organs (Anatomy); membranous lining of the embryonic body cavity (Embryology).

meningeal metastases
Cancer that has spread from the original (primary) tumor to the tissue covering the brain, spinal cord, or both.

metastasis (meh-TAS-ta-sis)
The spread of cancer from one part of the body to another. A tumor formed from cells that have spread is called a secondary tumor, a metastatic tumor, or a metastasis. The secondary tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-ta-seez).

prognosis (prog-NO-sis)
The likely outcome or course of a disease; the chance of recovery or recurrence.

TNM staging system
A system for describing the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).

tumor (TOO-mer)
An abnormal mass of tissue that results from excessive cell division. Tumors perform no useful body function. They may be benign (not cancerous) or malignant (cancerous).