Oligoastrocytomas are a subset of

brain tumor A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and seconda ...

s that present with an appearance of mixed glial cell origin,

astrocytoma Astrocytomas are a type of brain tumor. 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 usu ...

and

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 (9.4% of all primary brain and central nervous system tumors) but are also ...

. However, the term "Oligoastrocytoma" is now considered obsolete by the National Comprehensive Cancer Network stating "the term should no longer be used as such morphologically ambiguous tumors can be reliably resolved into astrocytomas and oligodendrogliomas with molecular testing." 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 42.5. Oligoastrocytomas, like

astrocytomas Astrocytomas are a type of brain tumor. 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 us ...

and oligodendrogliomas, can be divided into low-grade and

anaplastic Anaplasia (from grc, ἀνά ''ana'', "backward" + πλάσις ''plasis'', "formation") is a condition of cells with poor cellular differentiation, losing the morphological characteristics of mature cells and their orientation with respect to ...

variant, the latter characterized by high cellularity, conspicuous

cytologic Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...

atypism, mitotic activity and, in some cases, microvascular proliferation and

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

. However, lower grades can have less aggressive biology. These are largely

supratentorial In anatomy, the supratentorial region of the brain is the area located above the tentorium cerebelli. The area of the brain below the tentorium cerebelli is the infratentorial region. The supratentorial region contains the cerebrum, while the infr ...

tumors of adulthood that favor the frontal and temporal lobes.

Signs and symptoms

There are many possible symptoms of oligodendrogliomas that are similar to other

glioma A glioma is a type of tumor that starts in the glial cells of the brain or the spine. Gliomas comprise about 30 percent of all brain tumors and central nervous system tumours, and 80 percent of all malignant brain tumours. Signs and symptoms ...

s. These symptoms may include

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

and speech or motor changes.

Diagnosis

X-ray computed tomography An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 ...

(CT) or

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...

(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 A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

, like most tumors, relies on

histopathologic Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Spec ...

examination (

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...

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

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

and

radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

of doses and types ranging based upon the patient's needs. Subsequent MRI examination are often necessary to monitor the

resection cavity Resection may refer to: *Resection (surgery), the removal by surgery of all or part of an organ or other body structure *Segmental resection (or segmentectomy), the partial removal of an organ or other body structure * Position resection, a means o ...

Prognosis

Even after surgery, an oligoastrocytoma will often recur. The treatment for a recurring brain tumor may include surgical resection, chemotherapy and radiation therapy. Survival time of this brain tumor varies; younger age and low-grade initial diagnosis are factors in improved survival time.

References

External links

Brain and Spinal Tumors: Hope Through Research
from the U.S. (

National Institute of Neurological Disorders and Stroke The National Institute of Neurological Disorders and Stroke (NINDS) is a part of the U.S. National Institutes of Health (NIH). It conducts and funds research on brain and nervous system disorders and has a budget of just over US$2.03 billion. The ...

) {{Nervous tissue tumors Brain tumor