**15.2 High-grade astrocytomas**

Gross total resection is recommended for anaplastic astrocytomas. Local invasion of adjacent brain tissue is relatively common. Prognosis is poor for younger patients.

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*An Overview of Pediatric CNS Malignancies DOI: http://dx.doi.org/10.5772/intechopen.88189*

**15.3 Optic-hypothalamic glioma**

leading to hydrocephalus [42].

*15.3.1. Chemotherapy*

*15.3.2. Radiation*

**16. Brain stem tumors**

tine (CCNU), carmustine (BCNU) [40].

thalamus are considered as poor prognostic factors.

ally arise in the medulla, pons, or midbrain.

deficit and contralateral hemiparesis.

Pediatric brainstem gliomas occur as two major types: Focal brainstem gliomas, usually WHO grade I–II tumors.

astrocytomas (grade I) or fibrillary astrocytomas (grade II) [47].

remission

• Multiagent chemotherapy improve survivability with variable long-term

• Effective drugs alone or in combination: cisplatin, carboplatin, cyclophosphamide, ifosfamide, etoposide, topotecan, procarbazine, temozolomide, lomus-

Optic pathway-hypothalamic gliomas are rare astrocytic tumors that are more among young children. They comprise approximately 2% of all central nervous

OPG was classified by Dodge et al. into the following three stages: (A) limited to the optic nerve; (B) involving optic chiasma (with or without extension to the optic

The tumours do not produce symptoms at an early stage. The symptoms can be due to impingement on optic nerve or chiasma which leads to visual disturbances, involvement of hypothalamus causing endocrinopathies and hypothalamic dysfunction such as the diencephalic syndrome. It can also cause csf outflow block

Surgery has a limited role in the treatment of these tumours as they lie close to critical structures. It is usually limited to establishing a histopathological diagnosis or debulking in case of large tumours. Although Gross total resection of low-grade glioma is strongly associated with improvement of both OS and PFS but Aggressive resection, often leads to blindness, hypothalamic damage and cognitive dysfunctions [43].

Carboplatin and Vincristine is the most frequently recommended first-line chemotherapy, and it is considered to be the standard treatment of OPG [44].

Radiotherapy is considered as a treatment option for OPG but at a cost of long term complications of neurocognitive dysfunction and visual disturbances [45]. Radiation may therefore be useful for an adjuvant treatment in the case of chemotherapy refractory tumors. Prognosis depends upon the age of the patient and location of the tumour. Young age and tumour located in optic pathway and hypo-

Diffuse intrinsic pontine gliomas, range from WHO grade III–IV [46]. They usu-

**Focal brainstem gliomas (FBSG)**: constitutes approximately 20% of pediatric brainstem gliomas and usually occur outside the pons. Most are either pilocytic

FBSG is usually insidious in nature and the symptoms are related to site of tumour location. Most common symptoms include neck stiffness, cranial nerve

system tumors and account for 3–5% of pediatric intracranial tumors.

nerve) and (C) involvement of hypothalamus and other structures [41].

Depending on the degree of resectability, other treatment options are:

• Radiotherapy usually causes short-term and partial remission.

*Current Cancer Treatment*

16 years).

**15. Treatment**

scribed [38].

1.Young age.

6.Metastases.

**15.1 Low-grade astrocytomas**

4.Diencephalic syndrome.

**15.2 High-grade astrocytomas**

2.Diffuse histology, especially IDH-mutant.

5.Intracranial hypertension at initial presentation [39].

3.Inability to obtain a complete resection.

carry a very poor prognosis.

childhood (median age, approximately 10 years). They are almost exclusively midline, usually present in the thalamus, brain stem, and spinal cord, and

H3.3K27M cases are usually present between ages 5 and 10 years, accounting for approximately 60% of cases in the midline and pons. The prognosis for H3.3K27M patients is extremely poor, with a median survival of <1 year [35].

H3.1K27M cases present at a younger age than H3.3K27M cases and are

prognosis than do H3.3K27M cases (median survival, 15 vs. 11 months).

2.**H3.3 (***H3F3A***) mutation at G34**: The H3.3G34 subtype is associated with

age, 14–18 years) and arises exclusively in the cerebral cortex [36].

ric high-grade gliomas have DNA methylation patterns that are PXA-like [37].

Low-grade astrocytomas (grade I [pilocytic] and grade II) spread by direct extension; dissemination to other CNS sites is uncommon. Complete excision is the treatment of choice and the outcome is favorable especially if the tumor is circum-

Gross total resection is recommended for anaplastic astrocytomas. Local invasion of adjacent brain tissue is relatively common. Prognosis is poor for younger

Depending on the degree of resectability, other treatment options are:

• Radiotherapy usually causes short-term and partial remission.

Markers of poor prognosis for childhood low-grade astrocytomas are:

approximately 5 times less frequent. These cases have a slightly more favorable

mutations in *TP53* and *ATRX* which show widespread hypomethylation across the whole genome. It is common in older children and young adults (median

About 5% pediatric high-grade gliomas have *IDH1*-mutation. They are almost exclusively common in older adolescents (median age in a pediatric population,

**Pleomorphic xanthoastrocytoma (PXA)-like**: Approximately 10% of pediat-

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patients.

