Astrocytoma
   HOME

TheInfoList



OR:

Astrocytoma is a type of
brain tumor A brain tumor (sometimes referred to as brain cancer) occurs when a group of cells within the Human brain, brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign ...
. Astrocytomas (also astrocytomata) originate from a specific kind of star-shaped
glia Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. The neuroglia make up ...
l cell in the
cerebrum The cerebrum (: cerebra), telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfac ...
called an
astrocyte Astrocytes (from Ancient Greek , , "star" and , , "cavity", "cell"), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical control of en ...
. This type of tumor does not usually spread outside the brain and spinal cord, and it does not usually affect other organs. After
glioblastoma 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 nons ...
s, astrocytomas are the second most common
glioma A glioma is a type of primary tumor that starts in the glial cells of the brain or spinal cord. They are malignant but some are extremely slow to develop. Gliomas comprise about 30% of all brain and central nervous system tumors and 80% of ...
and can occur in most parts of the brain and occasionally in the spinal cord. Within the astrocytomas, two broad classes are recognized in literature, those with: * Narrow zones of infiltration (mostly noninvasive tumors; e.g., pilocytic astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images * Diffuse zones of infiltration (e.g., high-grade astrocytoma), that share various features, including the ability to arise at any location in the central nervous system, but with a preference for the cerebral hemispheres; they occur usually in adults, and have an intrinsic tendency to progress to more advanced grades. People can develop astrocytomas at any age. The low-grade type is more often found in children or young adults, while the high-grade type is more prevalent in adults. Astrocytomas in the base of the brain are more common in young people and account for roughly 75% of neuroepithelial tumors.


Pathophysiology

Astrocytoma causes regional effects by compression, invasion, and destruction of brain
parenchyma upright=1.6, Lung parenchyma showing damage due to large subpleural bullae. Parenchyma () is the bulk of functional substance in an animal organ such as the brain or lungs, or a structure such as a tumour. In zoology, it is the tissue that ...
, arterial and venous hypoxia, competition for nutrients, release of metabolic end products (e.g., free radicals, altered electrolytes, neurotransmitters), and release and recruitment of cellular mediators (e.g., cytokines) that disrupt normal parenchymal function. Secondary clinical sequelae may be caused by elevated
intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adu ...
attributable to direct mass effect, increased blood volume, or increased cerebrospinal fluid volume.


Genetic and Molecular alterations

Homozygous deletion of CDKN2A/B is the main feature of high grade astrocytoma. In addition, a genome-wide pattern of DNA copy-number alterations (CNAs) has been uncovered, which is correlated with a patient's survival and response to treatment. This pattern identifies among lower-grade astrocytoma patients a subtype, where the CNA genotype is correlated with an approximately one-year survival phenotype.


Diagnosis

An
X-ray computed tomography An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...
(CT) or
magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...
(MRI) scan is necessary to characterize the extent of these tumors (size, location, consistency). CT will usually show distortion of third and lateral ventricles with displacement of anterior and middle cerebral arteries. Histologic analysis is necessary for grading diagnosis. In the first stage of diagnosis the doctor will take a history of symptoms and perform a basic neurological exam, including an eye exam and tests of vision, balance, coordination, and mental status. The doctor will then require a CT scan and MRI of the patient's brain. During a CT scan, X-rays of the patient's brain are taken from many different directions. These are then combined by a computer, producing a cross-sectional image of the brain. For an MRI, the patient relaxes in a tunnel-like instrument while the brain is subjected to changes of magnetic field. An image is produced based on the behavior of the brain's water molecules in response to the magnetic fields. A special dye may be injected into a vein before these scans to provide contrast and make tumors easier to identify. If a tumor is found, a neurosurgeon must perform a biopsy on it. This simply involves the removal of a small amount of tumor tissue, which is then sent to a neuropathologist for examination and grading. The biopsy may take place before surgical removal of the tumor or the sample may be taken during surgery. Grading of the tumor sample is a method of classification that helps the doctor to determine the severity of the astrocytoma and to decide on the best treatment options. The neuropathologist grades the tumor by looking for atypical cells, the growth of new blood vessels, and for indicators of cell division called mitotic figures. File:Astrozytom.jpg, Low grade astrocytoma of the midbrain (lamina tecti), sagittal T1-weighted magnetic resonance imaging after contrast medium administration: The tumor is marked with an arrow. The CSF spaces in front of the tumor are expanded due to compression-induced hydrocephalus internus. Image:Gemistocytic Astrocytoma 003.jpg, A pathological specimen of a gemistocytic astrocytoma File:MRI Slices - 2007 and 2014 of astrocytoma patient - Steven Keating.jpg,
MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...
scans of an astrocytoma patient, showing tumor progression over the course of seven years


Grading

Of numerous grading systems in use for the classification of tumor of the central nervous system, the
World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...
(WHO) grading system is commonly used for astrocytoma. Established in 1993 in an effort to eliminate confusion regarding diagnoses, the WHO system established a four-tiered histologic grading guideline for astrocytomas that assigns a grade from 1 to 4, with 1 being the least aggressive and 4 being the most aggressive. The WHO grading scheme is based on the appearance of certain characteristics: atypia,
mitosis Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ...
, endothelial proliferation, and
necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...
. These features reflect the malignant potential of the tumor in terms of invasion and growth rate. Various types of astrocytomas are given these WHO grades: According to the WHO data, the lowest grade astrocytomas (grade I) make up only 2% of recorded astrocytomas, grade II 8%, and the higher grade anaplastic astrocytomas (grade III) 20%. The highest graded astrocytoma (grade IV GBM) is the most common primary nervous system cancer and second most frequent brain tumor after brain metastasis. Despite the low incidence of astrocytomas compared to other human cancers, mortality is significant, as the higher grades (III & IV) present high mortality rates (mainly due to late detection of the neoplasm).


Prevention

There are no precise guidelines because the exact cause of astrocytoma is not known.


Treatment

For low-grade astrocytomas, removal of the tumor generally allows functional survival for many years. In some reports, the 5-year survival has been over 90% with well-resected tumors. Indeed, broad intervention of low-grade conditions is a contested matter. In particular, pilocytic astrocytomas are commonly indolent bodies that may permit normal neurologic function. However, left unattended, these tumors may eventually undergo neoplastic transformation. To date hen? complete resection of high-grade astrocytomas is impossible because of the diffuse infiltration of tumor cells into normal parenchyma. Thus, high-grade astrocytomas inevitably recur after initial surgery or therapy and are usually treated similarly to the initial tumor. Despite decades of therapeutic research, curative intervention is still nonexistent for high-grade astrocytomas; patient care ultimately focuses on palliative management.


Society and culture


Notable cases

In March 1990,
United States Republican Party The Republican Party, also known as the Grand Old Party (GOP), is a Right-wing politics, right-wing political parties in the United States, political party in the United States. One of the Two-party system, two major parties, it emerged as t ...
political strategist Lee Atwater was diagnosed with astrocytoma after a tumor was found in his right
parietal lobe The parietal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integra ...
. After undergoing radiation therapy (including the then-new implant radiation treatment), Atwater died the following year at the age of 40. Long-time U.S. Senator Ted Kennedy (D-MA) died of malignant glioma. University of Texas sniper Charles Whitman, who killed multiple people during a mass murder event in 1966, was diagnosed with astrocytoma post-mortem. The Connally Commission investigating the shooting disagreed, and identified it as a
glioblastoma 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 nons ...
, and concluded the tumor "conceivably could have contributed to his inability to control his emotions and actions". Major League pitcher Dan Quisenberry was diagnosed with grade IV astrocytoma in January 1998. He died age 45 in 1998 in Leawood, Kansas. Richard Burns, winner of the
2001 The year's most prominent event was the September 11 attacks against the United States by al-Qaeda, which Casualties of the September 11 attacks, killed 2,977 people and instigated the global war on terror. The United States led a Participan ...
World Rally Championship The World Rally Championship (abbreviated as WRC) is an international rallying series owned and governed by the Fédération Internationale de l'Automobile, FIA. Inaugurated in 1973, it is the oldest FIA world championship after Formula One. E ...
, was diagnosed with astrocytoma in 2003. Four years to the day after winning the World Rally Championship, on 25 November 2005, Burns died in
Westminster Westminster is the main settlement of the City of Westminster in Central London, Central London, England. It extends from the River Thames to Oxford Street and has many famous landmarks, including the Palace of Westminster, Buckingham Palace, ...
, London, aged 34, after having been in a coma for some days as a result of his brain tumour. Professional wrestler Matt Cappotelli was diagnosed with a grade 2/3 astrocytoma in December 2005, scuttling plans to promote Cappottelli to the main WWE roster. Cappotelli, who won a contract with WWE through the third season of their reality program ''Tough Enough'', was the
Ohio Valley Wrestling Ohio Valley Wrestling (OVW) is an American professional wrestling promotion, professional wrestling promotion and former developmental territory based in Louisville, Kentucky. The company is currently run by Al Snow, Matt Jones (radio host), Ma ...
Heavyweight Champion at the time of his diagnosis and vacated the title in February 2006 after confirming the tumor was cancerous. Cappotelli underwent successful surgery and chemotherapy, but was unable to return to active wrestling work. He did return to OVW as a trainer in 2013. He died on June 29, 2018.


References

Bibliography * "Astrocytomas." KidsHealth - the Web's most visited site about children's health. Web. 01 May 2024
KidsHealth.org - Nemours KidsHealth
* "Astrocytoma - Diagnosis and Treatment Options at Mayo Clinic." Mayo Clinic: Medical Treatment and Research Centers. Web. 07 Dec. 2009

* "Glioblastoma Multiforme Treatment at Mayo Clinic." Mayo Clinic: Medical Treatment and Research Centers. Web. 07 Dec. 2009




External links

* ttps://www.cancer.net/cancer-types/astrocytoma-childhood Cancer.Net: Astrocytoma, Childhood
Imaging Astrocytoma
MR, CT, Pathology {{Nervous tissue tumors, state=collapsed Brain tumor Nervous system neoplasia