Oligoastrocytoma
Encyclopedia
Oligoastrocytomas are a subset of brain tumor
s that present with an appearance of mixed glial cell origin, astrocytoma
and oligodendroglioma
. These types of glial cells that become cancerous are involved with insulating and regulating the activity of neuron cells in the central nervous system. Often called a "mixed glioma", about 2.3% of all reported brain tumors are diagnosed as oligoastrocytoma. The median age of diagnosis is 42 years of age.
Oligoastrocytomas, like astrocytomas and oligodendrogliomas, can be divided into low-grade and anaplastic
variant, the latter characterized by high cellularity, conspicuous cytologic
atypism, mitotic activity and, in some cases, microvascular proliferation and necrosis
.
However, lower grades can have less aggressive biology.
These are largely supratentorial tumors of adulthood that favor the frontal and temporal lobes.
s. These symptoms may include headache
, seizure
and speech or motor changes.
(MRI) scan is necessary to characterize the anatomy of this tumor as to size, location, and its heter/homogeneity. However, final diagnosis of this tumor
, like most tumors, relies on histopathologic examination (biopsy
examination).
and radiation therapy
of doses and types ranging based upon the patient's needs. Subsequent MRI examination are often necessary to monitor the resection cavity.
Brain tumor
A brain tumor is an intracranial solid neoplasm, a tumor within the brain or the central spinal canal.Brain tumors include all tumors inside the cranium or in the central spinal canal...
s that present with an appearance of mixed glial cell origin, astrocytoma
Astrocytoma
Astrocytomas are a type of neoplasm of the brain. They originate in a particular kind of glial-cells, star-shaped brain cells in the cerebrum called astrocytes. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs...
and oligodendroglioma
Oligodendroglioma
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...
. These types of glial cells that become cancerous are involved with insulating and regulating the activity of neuron cells in the central nervous system. Often called a "mixed glioma", about 2.3% of all reported brain tumors are diagnosed as oligoastrocytoma. The median age of diagnosis is 42 years of age.
Oligoastrocytomas, like astrocytomas and oligodendrogliomas, can be divided into low-grade and anaplastic
Anaplasia
Anaplasia refers to a reversion of differentiation in cells and is characteristic of malignant neoplasms . Sometimes, the term also includes an increased capacity for multiplication. Lack of differentiation is considered a hallmark of aggressive malignancies. The term anaplasia literally means "to...
variant, the latter characterized by high cellularity, conspicuous cytologic
Cytopathology
Cytopathology is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by Rudolf Virchow in 1858. A common application of cytopathology is the Pap smear, used as a screening tool, to detect precancerous cervical lesions and prevent cervical...
atypism, mitotic activity and, in some cases, microvascular proliferation and necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
.
However, lower grades can have less aggressive biology.
These are largely supratentorial tumors of adulthood that favor the frontal and temporal lobes.
Symptoms
There are many possible symptoms of oligodendrogliomas that are similar to other gliomaGlioma
A glioma is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain.-By type of cell:...
s. These symptoms may include headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
and speech or motor changes.
Diagnosis
A Computed Tomography (CT) or Magnetic Resonance ImagingMagnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(MRI) scan is necessary to characterize the anatomy of this tumor as to size, location, and its heter/homogeneity. However, final diagnosis of this 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...
, like most tumors, relies on histopathologic examination (biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
examination).
Treatment
If resected, the surgeon will remove as much of this tumor as possible, without disturbing eloquent regions of the brain (speech/motor cortex) and other critical brain structure. Thereafter, treatment may include chemotherapyChemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
and radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
of doses and types ranging based upon the patient's needs. Subsequent MRI examination are often necessary to monitor the resection cavity.
Prognosis
Even after surgery, an oligoastrocytoma will often recur. The treatment for a recurring brain tumor may include surgical resection, chemo and radiation therapy. Survival time of this brain tumor varies - younger age and low-grade initial diagnosis are factors in improved survival time.External links
- Samantha Dickson Brain Tumour Trust: brain tumour research and support charity
- SDBTT Astro Fund, funding research and offering support to those affected by low-grade oligoastrocytomas
- Brain and Spinal Tumors: Hope Through Research from the U.S. (National Institute of Neurological Disorders and StrokeNational Institute of Neurological Disorders and StrokeThe National Institute of Neurological Disorders and Stroke is a part of the U.S. National Institutes of Health . It conducts and funds research on brain and nervous system disorders and has a budget of just over US$1.5 billion...
) - Images from the Uniformed Services University of the Health SciencesUniformed Services University of the Health SciencesThe Uniformed Services University of the Health Sciences is a health science university run by the U.S. federal government. The primary mission of the school is to prepare graduates for service to the U.S. at home and abroad in the medical corps....