|
|
| Line 13: |
Line 13: |
| }} | | }} |
| {{Astrocytoma}} | | {{Astrocytoma}} |
| | {{CMG}} |
| | ==[[Astrocytoma overview|Overview]]== |
|
| |
|
| {{CMG}}
| | ==[[Astrocytoma pathophysiology|Pathophysiology]]== |
| ==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]]. The [[WHO]] has given a four point scale depending on the histologic grade of the tumor (''see below''). This article focuses on the well-differentiated (Grade 2) astrocytoma. For grade 1 and 4 astrocytomas, see respective article headings:
| | ==[[Astrocytoma epidemiology and demographics|Epidemiology and Demographics]]== |
| {{main|pilocytic astrocytoma|glioblastoma multiforme}}
| |
|
| |
|
| ==Pathogenesis== | | ==[[Astrocytoma risk factors|Risk Factors]]== |
| Well-differentiated astrocytomas constitute about 25 to 30% of cerebral [[gliomas]]. They have a predilection for the [[cerebrum]], [[cerebellum]], [[hypothalamus]], [[pons]], and [[optic nerve]] and [[optic chiasm|chiasm]]. Although astrocytomas have many different histological characteristics, the most common type is the well-differentiated fibrillary astrocytoma. These tumors [[gene expression|express]] [[glial fibrillary acidic protein]] (GFAP), which possibly functions as a tumor suppressor<ref>{{cite journal
| |
| | author =M Toda ''et al''
| |
| | title =Cell growth suppression of astrocytoma C6 cells by glial fibrillary acidic protein cDNA transfection
| |
| | journal =Journal of Neurochemistry
| |
| | volume =63
| |
| | issue =5
| |
| | pages =1975-1978
| |
| | date =1994
| |
| | id =PMID 7931355 }}</ref>, and is a useful diagnostic marker in a tissue biopsy. <ref>{{cite journal
| |
| | author =JHN Deck ''et al''
| |
| | title = The role of glial fibrillary acidic protein in the diagnosis of central nervous system tumors
| |
| | journal =Acta Neuropathologica
| |
| | volume =42
| |
| | issue =3
| |
| | pages =183-190
| |
| | publisher =Springer Berlin / Heidelberg
| |
| | date =1978
| |
| | doi =10.1007/BF00690355}}
| |
| </ref>
| |
|
| |
|
| ===Grading===
| |
| Astrocytomas have great variation in their presentation. The [[World Health Organization]] acknowledges the following grading system for astrocytomas:
| |
| * '''Grade 1''' — [[pilocytic astrocytoma]] - primarily pediatric tumor, with median age at diagnosis of 12
| |
| * '''Grade 2''' — diffuse astrocytoma
| |
| * '''Grade 3''' — anaplastic (malignant) astrocytoma
| |
| * '''Grade 4''' — [[glioblastoma multiforme]] (most common)
| |
|
| |
|
| In addition to these four tumor grades, astrocytomas may combine with oligodendrocytes to produce [[oligoastrocytoma]]. Unique astrocytoma variants have also been known to exist.
| | ==[[Astrocytoma screening|Screening]]== |
|
| |
|
| ==Symptoms== | | ==[[Astrocytoma natural history|Natural History, Complications and Prognosis]]== |
| In almost half of the cases, the first symptom of an astrocytoma is the onset of a focal or generalized [[seizure]]. Between 60 to 75% of patients will have recurrent seizures in the course of their illness. Headache and signs of [[increased intracranial pressure]] ([[headache]], [[vomiting]]) usually present late in the disease course.
| |
|
| |
|
| In children, the tumor is usually located in the cerebellum and will present with some combination of vision deterioration (which is typically uncorrectable by glasses), gait instability, unilateral ataxia, and signs of increased intracranial pressure (headache, vomiting).
| | ==[[Astrocytoma classification|Classification]]== |
|
| |
|
| Children with astrocytoma usually have decreased memory, attention, and motor abilities, but unaffected intelligence, language, and academic skills. <ref>{{cite journal
| | ==[[Astrocytoma causes|Causes]]== |
| | author = JL Ater ''et al''
| |
| | title = Correlation of medical and neurosurgical events with neuropsychological status in children at diagnosis of astrocytoma: utilization of a neurological severity score
| |
| | journal = Journal of Child Neurology
| |
| | volume =11
| |
| | issue =6
| |
| | pages =462-469
| |
| | date =1996
| |
| | id =PMID 9120225}} </ref> When [[metastasis]] occurs, it can spread via the lymphatic system, causing death even when the primary tumor is well controlled.<ref>{{cite journal
| |
| | author =JM Dewar, PJ Dady and V Balakrishnan
| |
| | title =Metastatic astrocytoma
| |
| | journal =Australian and New Zealand Journal of Medicine
| |
| | volume =15
| |
| | issue =6
| |
| | pages =745-747
| |
| | date =1985
| |
| | id =PMID 3010926}}</ref>
| |
|
| |
|
| ==Diagnosis== | | ==[[Astrocytoma differential diagnosis|Differentiating Astrocytoma from other Disorders]]== |
|
| |
|
| A [[Computed Tomography]] (CT) or [[Magnetic Resonance Imaging]] (MRI) scan is necessary to characterize the anatomy of this tumor (size, location, consistency). CT will usually show distortion of third and lateral ventricles with displacement of anterior and middle cerebral arteries.
| | == Diagnosis == |
|
| |
|
| Histologic diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumor. The tumor may be cavitating, pseudocyst-forming, or noncavitating. Appearance is usually white-gray, firm, and almost indistinguishable from normal white matter.
| | :[[Astrocytoma history and symptoms| History and Symptoms]] | [[Astrocytoma physical examination | Physical Examination]] | [[Astrocytoma staging | Staging]] | [[Astrocytoma laboratory studies | Lab Studies]] | [[Astrocytoma electrocardiogram|Electrocardiogram]] | [[Astrocytoma chest x ray|Chest X Ray]] | [[Astrocytoma MRI|MRI]] | [[Astrocytoma CT|CT]] | [[Astrocytoma echocardiography|Echocardiography]] | [[Astrocytoma other imaging findings|Other imaging findings]] |
|
| |
|
| ==Treatment== | | ==Treatment== |
| Resection of the tumor will generally allow functional survival for many years. In recent reports, the 5 year survival has been over 90% with well resected tumors. These tumors will eventually undergo malignant transformation and addition of radiation therapy or chemotherapy will be necessary. Astrocytomas often recur even after treatment and are usually treated similarly as the initial tumor, with sometimes more aggressive chemotherapy or radiation therapy. In some rare cases, the tumor creates two or more cell types, and treatment may kill one cell type while allowing the other to become more aggressive and immune to future treatments.
| |
|
| |
|
| ==References==
| | :'''Medical:''' [[Astrocytoma medical therapy| Medical Therapy]] |
| {{Reflist|2}}
| | |
| | :'''Surgical:''' [[Astrocytoma surgery| Surgery]] |
|
| |
|
| | ==Case Studies== |
| ==See also== | | ==See also== |
| * [[glioma]] | | * [[glioma]] |