Nerve sheath tumor
Encyclopedia
A nerve sheath tumor is a type of tumor
of the nervous system
(nervous system neoplasm
) which is made up primarily of the myelin
surrounding nerve
s.
A peripheral nerve sheath tumor (PNST) is a nerve sheath tumor in the peripheral nervous system
.
Benign
peripheral nerve sheath tumors include schwannoma
s and neurofibroma
s.
A malignant peripheral nerve sheath tumor
(MPNST) is a cancer
ous peripheral nerve sheath tumor.
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
of the nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
(nervous system neoplasm
Nervous system neoplasm
A nervous system neoplasm is a tumor affecting the nervous system. Types include:* Brain tumor* Arachnoid cyst* Optic nerve glioma...
) which is made up primarily of the myelin
Myelin
Myelin is a dielectric material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination...
surrounding nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
s.
A peripheral nerve sheath tumor (PNST) is a nerve sheath tumor in the peripheral nervous system
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
.
Benign
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
peripheral nerve sheath tumors include schwannoma
Schwannoma
A schwannoma is a benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves....
s and neurofibroma
Neurofibroma
A neurofibroma is a benign nerve sheath tumor in the peripheral nervous system. Usually found in individuals with neurofibromatosis type I , an autosomal dominant genetically-inherited disease, they can result in a range of symptoms from physical disfiguration and pain to cognitive disability...
s.
A malignant peripheral nerve sheath tumor
Malignant peripheral nerve sheath tumor
A malignant peripheral nerve sheath tumor is a form of cancer of the connective tissue surrounding nerves. Given its origin and behavior it is classified as a sarcoma...
(MPNST) is a cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
ous peripheral nerve sheath tumor.