NEOPLASMS OF THE CENTRAL NERVOUS SYSTEM
Neoplasms may be classified according to localisation and histological features. Histological classification can be sub-divided according to whether the cells are:
- Normally present within the cranial or spinal cavity.
- Derived from the skull or spine.
- Represent cells that are not normal components of the central nervous system, usually representing embryonal components.
- Metastatic deposits from elsewhere in the body.
Cells that are normally present within the cranial or spinal cavities include:
Glial cells (astrocytes, oligodendrocytes or ependymal).
Primitive cells of the embryonic neural canal (neuroblasts, medulloblasts and other forms of primitive neuroectodermal tumour, spongioblasts).
Connective tissue cells.
Neoplasms of the skull or spine include those derived from bone, cartilage, notochord, and their haemotological components.
Embryonal cells can produce a wide variety of types of neoplasm including neoplasms of mixed cell type and showing variable differentiation.
A wide variety of neoplasms can metastasise to the central nervous system.
Tumours of the Nervous System can be classified as follows : -
Mainly astrocytic: fibrillary, protoplasmic, gemistocytic, pilocytic, anaplastic, glioblastoma multiforme ( may contain a sarcoma-like component), astroblastoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma.
Ependymoma and subependymoma
- Choroid plexus tumours
- Primitive neuroectodermal tumours (PNET) and other embryonic tumours
Medulloblastoma, neuroblastoma, ependymoblastoma, pineoblastoma, spongioblastoma
- Tumours containing neurons
Gangliocytoma, ganglioglioma, ganglioneuroma, desmoplastic infantile ganglioglioma, neuroblastoma, dysembryoplastic neuroepithelial tumour, central neurocytoma, olfactory neuroblastoma
Meningothelial, transitional, fibroblastic, psammomatous, angiomatous are the main types
Atypical and malignant
Haemangiopericytoma occurs in the meninges but has now been separated off from the main group of meningiomas.
- Nerve sheath tumours
- Pituitary adenoma
- Dermoid and epidermoid cysts
- Lymphoma and plasma cell neoplasms
- Pineal and parapineal tumours
Germinoma, teratoma, pineal parenchymal tumours
- Tumours invading the nervous system from a local source
- Metastatic tumours