A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant (cancerous) tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
Nervous tissue, also called neural tissue, is the main tissue component of the nervous system. The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system (PNS) comprising the branching peripheral nerves. It is composed of neurons, also known as nerve cells, which receive and transmit impulses, and neuroglia, also known as glial cells or glia, which assist the propagation of the nerve impulse as well as provide nutrients to the neurons.
A glioma is a type of primary tumor that starts in the glial cells of the brain or spinal cord. They are cancerous but some are extremely slow to develop. Gliomas comprise about 30 percent of all brain tumors and central nervous system tumours, and 80 percent of all malignant brain tumours.
Oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a glial precursor cell. They occur primarily in adults but are also found in children.
Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing on nearby tissue. Many cases never produce symptoms. Occasionally seizures, dementia, trouble talking, vision problems, one sided weakness, or loss of bladder control may occur.
Glioblastoma, previously known as glioblastoma multiforme (GBM), is the most aggressive and most common type of cancer that originates in the brain, and has a very poor prognosis for survival. Initial signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Symptoms often worsen rapidly and may progress to unconsciousness.
Astrocytoma is a type of brain tumor. Astrocytomas originate from a specific kind of star-shaped glial cell in the cerebrum called an astrocyte. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs. After glioblastomas, astrocytomas are the second most common glioma and can occur in most parts of the brain and occasionally in the spinal cord.
This is a list of terms related to oncology. The original source for this list was the US National Cancer Institute's public domain Dictionary of Cancer Terms.
The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.
Neurofibromatosis type II is a genetic condition that may be inherited or may arise spontaneously, and causes benign tumors of the brain, spinal cord, and peripheral nerves. The types of tumors frequently associated with NF2 include vestibular schwannomas, meningiomas, and ependymomas. The main manifestation of the condition is the development of bilateral benign brain tumors in the nerve sheath of the cranial nerve VIII, which is the "auditory-vestibular nerve" that transmits sensory information from the inner ear to the brain. Besides, other benign brain and spinal tumors occur. Symptoms depend on the presence, localisation and growth of the tumor(s). Many people with this condition also experience vision problems. Neurofibromatosis type II is caused by mutations of the "Merlin" gene, which seems to influence the form and movement of cells. The principal treatments consist of neurosurgical removal of the tumors and surgical treatment of the eye lesions. Historically the underlying disorder has not had any therapy due to the cell function caused by the genetic mutation.
A ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor which most frequently occurs in the temporal lobes of children and young adults. They are mixed cell tumors containing both neural ganglionic cells and neural glial cell components.
Glial tumor is a general term for numerous tumors of the central nervous system, including astrocytomas, ependymal tumors, Oligodendroglioma, and primitive neuroectodermal tumors. The World Health Organization (WHO) classifies tumors into different categories according to severity and recurrence.The first tumor classified as grade I is called pilocytic astrocytoma and it is most commonly observed in children rather than adults. The next tumor is never common in the Dns called diffuse astrocytoma and it is considered a grade II, they are benign, or noncancerous, but can become malignant, meaning cancerous, as the tumor progresses. Grades III and grade IV are considered malignant astrocytomas. Anaplastic astrocytomas are considered by the WHO to be a grade III astrocytoma and Glioblastoma is a grade IV both are referred to high-grade glial tumors.
The giant-cell glioblastoma is a histological variant of glioblastoma, presenting a prevalence of bizarre, multinucleated giant cells.
The concept of grading of the tumors of the central nervous system, agreeing for such the regulation of the "progressiveness" of these neoplasias, dates back to 1926 and was introduced by P. Bailey and H. Cushing, in the elaboration of what turned out the first systematic classification of gliomas.
In the following, the grading systems present in the current literature are introduced. Then, through a table, the more relevant are compared.
Pediatric ependymomas are similar in nature to the adult form of ependymoma in that they are thought to arise from radial glial cells lining the ventricular system. However, they differ from adult ependymomas in which genes and chromosomes are most often affected, the region of the brain they are most frequently found in, and the prognosis of the patients. Children with certain hereditary diseases, such as neurofibromatosis type II (NF2), have been found to be more frequently afflicted with this class of tumors, but a firm genetic link remains to be established. Symptoms associated with the development of pediatric ependymomas are varied, much like symptoms for a number of other pediatric brain tumors including vomiting, headache, irritability, lethargy, and changes in gait. Although younger children and children with invasive tumor types generally experience less favorable outcomes, total removal of the tumors is the most conspicuous prognostic factor for both survival and relapse.
Papillary tumors of the pineal region were first described by A. Jouvet et al. in 2003 and were introduced in the World Health Organization (WHO) classification of central nervous system in 2007. Papillary Tumors of the Pineal Region are located on the pineal gland which is located in the center of the brain. The pineal gland is located on roof of the diencephalon. It is a cone-shaped structure dorsal to the midbrain tectum. The tumor appears to be derived from the specialized ependymal cells of the subcommissural organ. Papillary tumors of the central nervous system and particularly of the pineal region are very rare and so diagnosing them is extremely difficult.
Diffuse midline glioma, H3 K27-altered (DMG) is a fatal tumour that arises in midline structures of the brain, most commonly the brainstem, thalamus and spinal cord. When located in the pons it is also known as diffuse intrinsic pontine glioma (DIPG).
Angiocentric glioma (AG) refers to a rare neuroepithelial tumor when the superficial brain malignant cells enclose the brain vessels, commonly found in children and young adults. Initially identified in 2005 by Wang and his team from the University of Texas, AG was classified as Grade I by 2007 WHO Classification of Tumors of the Central Nervous System due to its benign clinical behavior, low proliferation index, and curative properties. AG primarily affects children and young adults at an average initial diagnosis age of 16 years old. Over 85% AG patients experience intractable seizures since childhood, especially partial epilepsy.
