Astrocytoma Clinical Presentation

Updated: Dec 07, 2017
  • Author: Benjamin Kennedy, MD; Chief Editor: Herbert H Engelhard, III, MD, PhD, FACS  more...
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Presentation

History

The type of neurological symptoms that result from an astrocytoma depends foremost on the site and extent of tumor growth in the central nervous system (CNS). Onset of any of the following symptoms should alert the clinician to the presence of a neurological disorder and indicate a requirement for further investigation (in particular, with imaging studies such as magnetic resonance imaging [MRI] or computed tomography [CT] scan, with and without contrast):

  • Altered mental status
  • Cognitive impairment
  • Headaches
  • Visual disturbances
  • Motor impairment
  • Seizures
  • Sensory anomalies
  • Ataxia

Astrocytomas of the spinal cord or brainstem are less common. Patients with these neoplasms present with motor/sensory or cranial nerve deficits referable to the tumor's location.

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Physical

A detailed neurological examination is required for the proper evaluation of any patient with an astrocytoma. Because these tumors may affect any part of the CNS, including the spinal cord, and may spread to distant regions of the CNS, a thorough physical examination referable to the entire neuraxis is necessary to define the location and extent of disease.

Special attention should be paid to manifestations of increased intracranial pressure (ICP), such as the following, to determine the risk of mass effect, hydrocephalus, and herniation:

  • Headache
  • Nausea and vomiting
  • Decreased alertness
  • Cognitive impairment
  • Papilledema
  • Ataxia

Localizing and lateralizing signs, including cranial nerve palsies, hemiparesis, sensory levels, alteration of deep tendon reflexes (DTRs), and the presence of pathological reflexes (eg, Hoffman and Babinski signs), should be noted. Once neurological abnormalities are identified, imaging studies should be sought for further evaluation.

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Causes

The etiology of diffuse astrocytomas has been the subject of analytic epidemiological studies that have yielded associations with various disorders and exposures. [10] With the exception of therapeutic irradiation [11] and, perhaps, nitroso compounds (eg, nitrosourea), the identification of specific causal environmental exposures or agents has been unsuccessful. Although concern has been raised regarding cell phone use as a potential risk factor for development of gliomas, studies have yielded conflicting results. [12, 13, 14, 15, 16]

Children receiving prophylactic irradiation for acute lymphoblastic leukemia (ALL) have a 22-fold increased risk of developing CNS neoplasms, including WHO grade II, III, and IV astrocytomas, with an interval for onset of 5-10 years. Furthermore, irradiation of pituitary adenomas has been demonstrated to carry a 16-fold increased risk of glioma formation. [17]

Evidence exists for genetic susceptibility to glioma development. For example, familial clustering of astrocytomas is well described in inherited neoplastic syndromes, such as Turcot syndrome, neurofibromatosis type 1 (NF1) syndrome, and p53 germ line mutations (eg, Li-Fraumeni syndrome). Biological investigation has implicated that mutations in specific molecular pathways, such as the p53-MDM2-p21 and p16-p15-CDK4-CDK6-RB pathways, are associated with astrocytoma development and progression.

In addition, inherited elements of the immune response known as human leukocyte antigens (HLA) have been both positively and negatively associated with an increased risk for the development of glioblastoma multiforme. Two-thirds of low-grade astrocytomas have p53 mutations. [18]

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