History
Patients often report a history of illness for more than 3 months prior to diagnosis.
Increased intracranial pressure
Initial symptoms are usually nonspecific, nonlocalizing, and related to increased intracranial pressure (ICP). These signs occur in as many as 75% of patients regardless of tumor location.
The classic triad of a raised ICP consists of morning headaches, vomiting, and lethargy. The headache is characterized by pain upon arising that is relieved by vomiting and lessens during the day.
School-aged children more commonly report vague intermittent headaches and fatigue. They may have a declining academic performance and may exhibit personality changes.
Infants may present with irritability, anorexia, developmental delay, or regression.
Leroy et al conducted a retrospective study to determine whether severe anorexia might be a harbinger of low-grade astrocytomas of the fourth ventricle in pediatric patients. [8] Their review included 34 patients (16 boys, 18 girls; mean age, 8 years) who underwent surgical treatment of low-grade astrocytoma between 1991 and 2012. Of the study cohort, 31 patients had pilocytic astrocytoma, and 3 had diffuse astrocytoma. Seven of the patients presented with notable anorexia; the average body mass index (BMI) in this group was ≤2 standard deviation (SD). Twenty-seven of the patients had no anorexia; the average BMI in this group was +1 SD. There were no significant differences in these groups with regard to hydrocephalus or tumor location. For all the children with anorexia, BMI improved markedly during the postoperative follow-up period, which lasted on average 6 years. The investigators concluded that unexplained or atypical anorexia, in association with negative etiologic assessment, should prompt cerebral imaging. They indicated that clinical improvement after surgical resection could suggest a possible interaction between tumor tissue and appetite-suppressing peptide secretion. [8]
Seizures
Seizures are present at diagnosis in at least 25% of patients with supratentorial astrocytomas. They may precede diagnosis by several months to 1-2 years.
Signs related to tumor location
Focal motor deficits occur in as many as 60% of patients with hemispheric and central diencephalic tumors. They are more common in individuals with high-grade gliomas.
Seizures occur in 30-50% of children, may be focal, and are a more common presenting finding in low-grade gliomas.
Hypothalamic tumors may be associated with neuroendocrine abnormalities, growth hormone deficiency, diabetes insipidus, and precocious pubertal development. These tumors may also impinge on the optic chiasm, resulting in optic atrophy and visual deficits.
Patients with diencephalic tumors may present with the classic diencephalic syndrome (ie, emesis, emaciation, unusual euphoria), but the syndrome is rare in children older than 3 years.
Patients with astrocytomas of the cerebellum may present with weakness, dysmetria, tremor, and ataxia.
Astrocytomas of the brain stem are characterized by the presence of isolated cranial nerve deficits and contralateral hemiparesis.
Astrocytomas of the visual pathways may be brought to medical attention because of strabismus, proptosis, nystagmus, or developmental delay. Young children rarely report the slow and progressive visual loss characteristic of these tumors. Infants frequently display head tilt, head bobbing, and nystagmus. Astrocytomas in children with neurofibromatosis type 1 (NF1) may be asymptomatic at the time of diagnosis and may be detected on screening studies.
Patients with astrocytomas of the spinal cord most frequently present with pain (70% of patients have pain localized to the vertebral segments adjacent to the tumor), weakness, gait disturbance, and sphincter dysfunction. Paresthesias and loss of sensation occur later in the disease course.
Physical Examination
Increased intracranial pressure
A funduscopic examination reveals papilledema. Infants may have only optic pallor.
Palsy of cranial nerve VI is common and results in the inability to abduct one or both eyes.
Infants may demonstrate the setting sun sign, observed as an impaired upgaze and a forced downward deviation of both eyes. Measurement of head circumference in infants with open sutures may reveal macrocephaly.
Other signs
Strength and motor testing may reveal weakness and monoplegia or hemiplegia.
Localized deficits in truncal steadiness, upper extremity coordination, and gait may be observed with tumors of the posterior fossa and basal ganglia.
Multiple and bilateral cranial nerve deficits, especially VI and VII; long tract signs; and ataxia are associated with brainstem tumors.
Visual acuity is frequently reduced to less than 20/200 with optic gliomas. The pattern of visual loss in those patients with intraorbital tumors is most commonly a decrease in central vision, whereas bitemporal hemianopsia is most often noted in those patients with chiasmatic tumors. The involved eye generally shows optic pallor and nystagmus. Mild proptosis is usually present with primary intraorbital tumors.
Spinal astrocytomas often cause weaknesses of a variable extent and severity, ranging from monoparesis to quadriparesis. Pain along the involved vertebral segment may occur when the patient sneezes or coughs. Papilledema and hydrocephaly are present in 15% of patients and are attributed to increased cerebrospinal fluid (CSF) viscosity from an elevated protein content.
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This MRI shows a pilocytic astrocytoma of the cerebellum.
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This MRI shows a supratentorial glioblastoma multiforme.
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This section displays the typical biphasic pattern of a pilocytic astrocytoma, consisting of dense, relatively anuclear, fibrillar areas alternating with looser cystic fields.
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This section displays the high cellularity, mitosis, and nuclear atypia characteristic of an anaplastic astrocytoma (grade III).
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This section displays a typical field of a glioblastoma multiforme (grade IV) with pseudopalisading neovascularity, nuclear atypia, numerous mitoses, and areas of hemorrhage.
