Astrocytoma overview: Difference between revisions
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{{Astrocytoma}} | {{Astrocytoma}} | ||
{{CMG}} | {{CMG}} {{AE}}, {{Fs}} | ||
==Overview== | ==Overview== | ||
Astrocytomas are primary intracranial [[tumor]]s derived from [[astrocyte]]s cells of the [[brain]]. They may arise in the [[cerebral hemispheres]], in the [[Posterior cranial fossa|posterior fossa]], in the [[optic nerve]], and rarely, the [[spinal cord]]. Astrocytomas are a type of [[neoplasm]] of the [[brain]]. They originate in a particular kind of [[Glial cell|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. | |||
==Historical Perspective== | |||
Astrocytoma was the first [[glioma]] [[tumor]] to be described. It was first explained as glioma duram by Virchow in 1840 and then as spider [[cell]] glioma by T.Simon in 1874 and astroma by M von Lenhossek in 1895. [[Histology|Histological]] description of astrocytoma was first given by Bergstrand in 1932. | |||
==Classification== | |||
Astrocytoma may be classified according to its [[histology]] into 4 grades: [[pilocytic astrocytoma]], [[diffuse astrocytoma]], anaplastic astrocytoma and [[glioblastoma multiforme]]. | |||
==Pathophysiology== | |||
The exact [[pathogenesis]] of astrocytoma is not completely understood but it is believed that this [[tumor]] has a close association with [[genetic mutations]]. Microscopic pathologic findings in [[pilocytic astrocytoma]] include normal cells with slow growth rate, biphasic pattern (dense fibrillar tissue within loose myxoid tissue), [[Calcification]], Vascular hyalinization and Nested fibrotic pattern. In [[diffuse astrocytoma]] we may see [[Atypia|atypical cells]], relatively slow [[mitosis]] rate, diffusely infiltrate [[neuropil]] and poorly defined [[cytoplasm]]. In [[anaplastic astrocytoma]] we may see [[Pleomorphism|pleomorphic]] and [[malignant]] cells, High [[mitosis]] rate, hyperchromatosis and prominent small [[Blood vessel|vessels]]. In [[Glioblastoma multiforme|glioblastoma multiform]] we may see [[Pleomorphism|Pleomorphic]] cells, Naked nuclei, Multi-focal [[necrosis]], Pseudopalisading pattern, Scattered pyknotic nuclear debris in the center, Micro-vascular proliferation and Vascular [[thrombi]]. | |||
==Causes== | |||
The exact cause of astrocytoma is not known but it seems that [[Genetic mutation]] has a strong association with this [[tumor]]. | |||
==Differential Diagnosis== | |||
Astrocytoma must be differentiated from other space occupying [[CNS]] lesions that cause neurological symptoms such as subependymal [[nodule]], central neurocytoma, [[oligodendroglioma]], intraventricular [[meningioma]], intraventricular [[metastasis]], [[medulloblastoma]], [[sarcoma]], primitive neuroectodermal [[tumor]], [[choroid plexus]] [[carcinoma]] and [[glioblastoma multiforme]]. | |||
==Epidemiology and Demographics== | |||
The [[incidence]] of astrocytoma is 0.23 per 100,000 and the number of new cases is 700 per year. In 2012, there were an estimated 148,818 people living with [[brain]] and other [[nervous system]] [[cancer]] in the United States. The number of deaths was 4.3 per 100,000 men and women per year based on 2008-2012 deaths. The [[Low grade astrocytoma|low-grade]] type is more often found in children or young adults, while the [[High grade astrocytoma|high-grade]] type is more prevalent in adults. [[Pilocytic astrocytoma]] is more common in men, who account for 62% of all cases. The male-to-female ratio of [[diffuse astrocytoma]] is 1.5:1 and for [[anaplastic astrocytoma]] is 1.8:1. Astrocytoma is more common in caucasian [[race]]. | |||
==Risk Factors== | |||
Common risk factors in the development of astrocytoma include environmental factors such as: [[Vinyl chloride]], [[Phenols]], organic solvents, [[Pesticide|pesticides]], [[Formaldehyde]], lubricating fluids, [[Polycyclic aromatic hydrocarbon|polycyclic aromatic hydrocarbons]] and past [[radiation therapy]] to the [[brain]] and genetic diseases such as: [[Neurofibromatosis]], [[Tuberous sclerosis]], [[Li-Fraumeni syndrome]], [[Nevoid basal cell carcinoma syndrome]], [[Turcot syndrome]] and Melanoma-astrocytoma syndrome. Less common risk factors include: [[Blood group|Blood group A]], previous [[head trauma]], history of [[meningitis]], history of [[epilepsy]]. | |||
==Natural History== | |||
If left untreated, eventually 100% of patients with [[Low grade astrocytoma|low grade astrocytomas]] will growth rapidly similar to [[high grade astrocytoma]] tumors and 100% of patients with [[high grade astrocytoma]] will become [[symptomatic]] and deteriorate. Astrocytoma being a space occupying [[lesion]] can have following complications depending on the location of the [[tumor]]: [[Increased intracranial pressure]], [[cognitive]] dysfunction, [[Emotional disorders|emotional disturbances]], behavioral complications, [[Visual disturbance|visual defects]] and [[Muscle weakness]]. [[Low grade astrocytoma|Low-grade astrocytomas]] (grade I [<nowiki/>[[Pilocytic astrocytoma|pilocytic]]] and grade II) have a relatively favorable [[prognosis]], particularly for circumscribed, grade I lesions where complete excision may be possible. [[High grade astrocytoma|High-grade astrocytomas]] generally carry a poor [[prognosis]] in younger patients. | |||
==History and Symptoms== | |||
A positive history of [[Vinyl chloride]], [[Phenols]][[Organic solvents|, organic solvents]], [[Pesticide|pesticides]], [[Formaldehyde]], lubricating fluids, [[Polycyclic aromatic hydrocarbon|polycyclic aromatic hydrocarbons]], past [[radiation therapy]] to the [[brain]], [[Genetic]] disorders, [[Blood group|blood group A]], previous [[head trauma]], [[Meningitis]], [[Epilepsy]], [[Headache]], limb [[Paresthesia|parasthesia]] or [[weakness]], difficulty [[swallowing]], [[Nausea]], [[Diplopia]], [[Lethargy]], personality changes and [[Blurred vision]] is suggestive of astrocytoma. The most common symptoms of astrocytoma include morning [[headache]] or [[headache]] that goes away after [[vomiting]], [[Nausea and vomiting]], [[Vision]], [[hearing]], and [[speech]] problems, loss of balance and trouble walking, worsening handwriting or slow [[speech]], [[Weakness]] or change in feeling on one side of the [[body]], unusual [[Sleep|sleepiness]], Change in personality or behavior, Increase in the size of the [[head]] (in [[Infant|infants]]), [[Seizures]], decreased [[memory]], [[attention]], and motor abilities, but unaffected intelligence, language, and academic skills. Less common symptoms of astrocytoma include [[Weight loss]] or [[weight]] gain for no known reason and more or less energy than usual. | |||
==Physical Examination== | |||
Common physical examination findings of astrocytoma include [[gait]] disturbances, [[Tachycardia]] or [[bradycardia]], [[Orthostatic hypotension]], reduced hearing acuity, [[nystagmus]], abnormal extra-ocular movement, nonreactive [[Pupil|pupils]], [[papilledema]], [[blurry vision]], head tilt, [[Altered mental status]], [[Clonus]] , [[Hyperreflexia]], [[Muscle rigidity]], proximal/distal muscle weakness unilaterally or bilaterally, [[Cranial nerves|cranial nerve]] involvement , unilateral/bilateral sensory loss in the upper/lower extremity, positive [[Trendelenburg's sign]], unilateral/bilateral [[tremor]] and [[Dysmetria]]. | |||
==Laboratory Findings== | |||
There are no diagnostic lab findings associated with astrocytoma. | |||
== Electrocardiogram == | |||
Frontal astrocytomas can disturb autonomic pathways and cause [[prolonged QT syndrome]]. | |||
== X Ray == | |||
There are no characteristic x-ray findings associated with astrocytomas. | |||
== Echocardiography/Ultrasound == | |||
There are no echocardiography/ultrasound findings associated with astrocytoma. | |||
==CT== | |||
[[CT scan]] may be helpful in the diagnosis of astrocytoma. Findings on [[CT scan]] suggestive of astrocytoma include: Poorly demarcated mass, low density and no inhancement inside the tumor In [[low grade astrocytoma]], poorly demarcated mass, low density and there are partial enhancement inside the [[tumor]] mas In [[high grade astrocytoma]]. | |||
==MRI== | |||
Findings on MRI suggestive of astrocytoma in [[Low grade astrocytoma]] ([[Pilocytic astrocytoma|pilocytic]] and [[diffuse astrocytoma]]) include Decreased resonance in comparison to surrounding brain tissue in T1 and Increased resonance in comparison to surrounding brain tissue in T2. In [[anaplastic astrocytoma]] we have Hypointense T1, Hyperintense T2 and some contrast enhancement and [[edema]]. In [[Glioblastoma multiforme|glioblastoma multiform]] we have irregular ring-nodular enhancing lesions and central [[necrosis]] surrounding [[vasogenic edema]]. | |||
== Other Imaging Findings == | |||
[[PET scan|PET]]/[[SPECT]] may be helpful in the differentiation of astrocytoma grading. Finding on [[PET scan|PET]]/[[SPECT]] suggestive of [[low grade astrocytoma]] is hypometabolic mass and finding on [[PET scan|PET]]/[[SPECT]] suggestive of [[high grade astrocytoma]] is hypermetabolic mass. | |||
==Other Diagnostic Studies== | |||
[[Biopsy]] is helpful in the diagnosis of astrocytomas. Findings suggestive diagnostic of astrocytoma include normal cells with slow growth rate, biphasic pattern (dense fibrillar tissue within loose myxoid tissue), [[Calcification]], Vascular hyalinization and Nested fibrotic pattern in [[pilocytic astrocytoma]], [[Atypia|atypical cells]], relatively slow mitosis rate, diffusely infiltrate [[neuropil]] and poorly defined [[cytoplasm]] in [[diffuse astrocytoma]], [[Pleomorphism|pleomorphic]] and [[malignant]] cells, High [[mitosis]] rate, hyperchromatosis and prominent small [[Blood vessel|vessels]] in [[anaplastic astrocytoma]], [[Pleomorphism|Pleomorphic]] cells, Naked nuclei, Multi-focal [[necrosis]], Pseudopalisading pattern, Scattered pyknotic nuclear debris in the center, Micro-vascular proliferation and Vascular [[thrombi]] in [[Glioblastoma multiforme|glioblastoma multiform]]. | |||
==Medical Therapy== | |||
The mainstay of treatment for [[low grade astrocytoma]] is wait and see approach, [[Radiation therapy|radiation]] therapy and [[chemotherapy]]. Treatment for [[anaplastic astrocytoma]] is [[radiotherapy]] with adjunctive [[chemotherapy]], [[Radiation therapy|radiotherapy]] alone and [[chemotherapy]] alone. Treatment for [[Glioblastoma multiforme|glioblastoma multiform]] is [[chemotherapy]] and [[Radiation therapy|radiotherapy]], [[Bevacizumab]], alternating electric fields and [[Carmustine]] polymer wafers. | |||
==Surgery== | |||
Surgical intervention is the mainstay of treatment for astrocytomas. Extensive resection is preferred over partial resection. The relative [[Contraindication|contraindications]] of brain [[surgery]] are: Advanced age, sever [[cardiopulmonary]] dysfunction, inaccessible lesions and sever systemic illness such as [[sepsis]]. | |||
== Primary Prevention == | |||
Effective measures for the primary [[prevention]] of astrocytoma include eliminating environmental [[Risk factor|risk factors]] from happening such as: Exposure to [[Vinyl chloride]], [[Phenols]], [[Organic solvents]], [[Pesticide|Pesticides]], [[Formaldehyde]], Lubricating fluids, [[Polycyclic aromatic hydrocarbon|Polycyclic aromatic hydrocarbons]] and Previous [[Radiation therapy|radiation]] to the [[brain]]. | |||
== Secondary Prevention == | |||
There are no established measures for the secondary prevention of astrocytoma. | |||
==References== | ==References== | ||
{{reflist|2}} | {{reflist|2}} | ||
{{Nervous tissue tumors}} | {{Nervous tissue tumors}} | ||
[[pt:Astrocitoma]] | [[pt:Astrocitoma]] | ||
{{WikiDoc Help Menu}} | {{WikiDoc Help Menu}} | ||
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[[Category:Pathology]] | [[Category:Pathology]] | ||
[[Category:Neurosurgery]] | [[Category:Neurosurgery]] | ||
[[Category:Up-To-Date]] | |||
[[Category:Oncology]] | [[Category:Oncology]] | ||
[[Category:Medicine]] | |||
Latest revision as of 19:48, 14 January 2019
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: , Fahimeh Shojaei, M.D.
Overview
Astrocytomas are primary intracranial tumors derived from astrocytes cells of the brain. They may arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve, and rarely, the spinal cord. 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.
Historical Perspective
Astrocytoma was the first glioma tumor to be described. It was first explained as glioma duram by Virchow in 1840 and then as spider cell glioma by T.Simon in 1874 and astroma by M von Lenhossek in 1895. Histological description of astrocytoma was first given by Bergstrand in 1932.
Classification
Astrocytoma may be classified according to its histology into 4 grades: pilocytic astrocytoma, diffuse astrocytoma, anaplastic astrocytoma and glioblastoma multiforme.
Pathophysiology
The exact pathogenesis of astrocytoma is not completely understood but it is believed that this tumor has a close association with genetic mutations. Microscopic pathologic findings in pilocytic astrocytoma include normal cells with slow growth rate, biphasic pattern (dense fibrillar tissue within loose myxoid tissue), Calcification, Vascular hyalinization and Nested fibrotic pattern. In diffuse astrocytoma we may see atypical cells, relatively slow mitosis rate, diffusely infiltrate neuropil and poorly defined cytoplasm. In anaplastic astrocytoma we may see pleomorphic and malignant cells, High mitosis rate, hyperchromatosis and prominent small vessels. In glioblastoma multiform we may see Pleomorphic cells, Naked nuclei, Multi-focal necrosis, Pseudopalisading pattern, Scattered pyknotic nuclear debris in the center, Micro-vascular proliferation and Vascular thrombi.
Causes
The exact cause of astrocytoma is not known but it seems that Genetic mutation has a strong association with this tumor.
Differential Diagnosis
Astrocytoma must be differentiated from other space occupying CNS lesions that cause neurological symptoms such as subependymal nodule, central neurocytoma, oligodendroglioma, intraventricular meningioma, intraventricular metastasis, medulloblastoma, sarcoma, primitive neuroectodermal tumor, choroid plexus carcinoma and glioblastoma multiforme.
Epidemiology and Demographics
The incidence of astrocytoma is 0.23 per 100,000 and the number of new cases is 700 per year. In 2012, there were an estimated 148,818 people living with brain and other nervous system cancer in the United States. The number of deaths was 4.3 per 100,000 men and women per year based on 2008-2012 deaths. The low-grade type is more often found in children or young adults, while the high-grade type is more prevalent in adults. Pilocytic astrocytoma is more common in men, who account for 62% of all cases. The male-to-female ratio of diffuse astrocytoma is 1.5:1 and for anaplastic astrocytoma is 1.8:1. Astrocytoma is more common in caucasian race.
Risk Factors
Common risk factors in the development of astrocytoma include environmental factors such as: Vinyl chloride, Phenols, organic solvents, pesticides, Formaldehyde, lubricating fluids, polycyclic aromatic hydrocarbons and past radiation therapy to the brain and genetic diseases such as: Neurofibromatosis, Tuberous sclerosis, Li-Fraumeni syndrome, Nevoid basal cell carcinoma syndrome, Turcot syndrome and Melanoma-astrocytoma syndrome. Less common risk factors include: Blood group A, previous head trauma, history of meningitis, history of epilepsy.
Natural History
If left untreated, eventually 100% of patients with low grade astrocytomas will growth rapidly similar to high grade astrocytoma tumors and 100% of patients with high grade astrocytoma will become symptomatic and deteriorate. Astrocytoma being a space occupying lesion can have following complications depending on the location of the tumor: Increased intracranial pressure, cognitive dysfunction, emotional disturbances, behavioral complications, visual defects and Muscle weakness. Low-grade astrocytomas (grade I [pilocytic] and grade II) have a relatively favorable prognosis, particularly for circumscribed, grade I lesions where complete excision may be possible. High-grade astrocytomas generally carry a poor prognosis in younger patients.
History and Symptoms
A positive history of Vinyl chloride, Phenols, organic solvents, pesticides, Formaldehyde, lubricating fluids, polycyclic aromatic hydrocarbons, past radiation therapy to the brain, Genetic disorders, blood group A, previous head trauma, Meningitis, Epilepsy, Headache, limb parasthesia or weakness, difficulty swallowing, Nausea, Diplopia, Lethargy, personality changes and Blurred vision is suggestive of astrocytoma. The most common symptoms of astrocytoma include morning headache or headache that goes away after vomiting, Nausea and vomiting, Vision, hearing, and speech problems, loss of balance and trouble walking, worsening handwriting or slow speech, Weakness or change in feeling on one side of the body, unusual sleepiness, Change in personality or behavior, Increase in the size of the head (in infants), Seizures, decreased memory, attention, and motor abilities, but unaffected intelligence, language, and academic skills. Less common symptoms of astrocytoma include Weight loss or weight gain for no known reason and more or less energy than usual.
Physical Examination
Common physical examination findings of astrocytoma include gait disturbances, Tachycardia or bradycardia, Orthostatic hypotension, reduced hearing acuity, nystagmus, abnormal extra-ocular movement, nonreactive pupils, papilledema, blurry vision, head tilt, Altered mental status, Clonus , Hyperreflexia, Muscle rigidity, proximal/distal muscle weakness unilaterally or bilaterally, cranial nerve involvement , unilateral/bilateral sensory loss in the upper/lower extremity, positive Trendelenburg's sign, unilateral/bilateral tremor and Dysmetria.
Laboratory Findings
There are no diagnostic lab findings associated with astrocytoma.
Electrocardiogram
Frontal astrocytomas can disturb autonomic pathways and cause prolonged QT syndrome.
X Ray
There are no characteristic x-ray findings associated with astrocytomas.
Echocardiography/Ultrasound
There are no echocardiography/ultrasound findings associated with astrocytoma.
CT
CT scan may be helpful in the diagnosis of astrocytoma. Findings on CT scan suggestive of astrocytoma include: Poorly demarcated mass, low density and no inhancement inside the tumor In low grade astrocytoma, poorly demarcated mass, low density and there are partial enhancement inside the tumor mas In high grade astrocytoma.
MRI
Findings on MRI suggestive of astrocytoma in Low grade astrocytoma (pilocytic and diffuse astrocytoma) include Decreased resonance in comparison to surrounding brain tissue in T1 and Increased resonance in comparison to surrounding brain tissue in T2. In anaplastic astrocytoma we have Hypointense T1, Hyperintense T2 and some contrast enhancement and edema. In glioblastoma multiform we have irregular ring-nodular enhancing lesions and central necrosis surrounding vasogenic edema.
Other Imaging Findings
PET/SPECT may be helpful in the differentiation of astrocytoma grading. Finding on PET/SPECT suggestive of low grade astrocytoma is hypometabolic mass and finding on PET/SPECT suggestive of high grade astrocytoma is hypermetabolic mass.
Other Diagnostic Studies
Biopsy is helpful in the diagnosis of astrocytomas. Findings suggestive diagnostic of astrocytoma include normal cells with slow growth rate, biphasic pattern (dense fibrillar tissue within loose myxoid tissue), Calcification, Vascular hyalinization and Nested fibrotic pattern in pilocytic astrocytoma, atypical cells, relatively slow mitosis rate, diffusely infiltrate neuropil and poorly defined cytoplasm in diffuse astrocytoma, pleomorphic and malignant cells, High mitosis rate, hyperchromatosis and prominent small vessels in anaplastic astrocytoma, Pleomorphic cells, Naked nuclei, Multi-focal necrosis, Pseudopalisading pattern, Scattered pyknotic nuclear debris in the center, Micro-vascular proliferation and Vascular thrombi in glioblastoma multiform.
Medical Therapy
The mainstay of treatment for low grade astrocytoma is wait and see approach, radiation therapy and chemotherapy. Treatment for anaplastic astrocytoma is radiotherapy with adjunctive chemotherapy, radiotherapy alone and chemotherapy alone. Treatment for glioblastoma multiform is chemotherapy and radiotherapy, Bevacizumab, alternating electric fields and Carmustine polymer wafers.
Surgery
Surgical intervention is the mainstay of treatment for astrocytomas. Extensive resection is preferred over partial resection. The relative contraindications of brain surgery are: Advanced age, sever cardiopulmonary dysfunction, inaccessible lesions and sever systemic illness such as sepsis.
Primary Prevention
Effective measures for the primary prevention of astrocytoma include eliminating environmental risk factors from happening such as: Exposure to Vinyl chloride, Phenols, Organic solvents, Pesticides, Formaldehyde, Lubricating fluids, Polycyclic aromatic hydrocarbons and Previous radiation to the brain.
Secondary Prevention
There are no established measures for the secondary prevention of astrocytoma.