Childhood Brain Tumors

Central nervous system (CNS) tumors in children vary due to histological types and clinical behavior.

Central nervous system (CNS) tumors in children vary due to histological types and clinical behavior. All childhood cancers are most 3rd frequent in Turkey , In the United States and in developed countries is the most 2nd common pediatric tumor group. While only 1% of all tumors in adults are brain tumors, in children, after the blood cancers (such as leukemia and lymphoma), is the most common brain tumors. 20% of all childhood tumors are brain tumors. In adults, only 10% of brain tumors are located in the cerebellum, while in children 50% are located in the cerebellum and brain stem.

In childhood brain tumors, the benign ones are relatively small. At least 50% is malignant. Unlike adult tumors, it tends to spread to different parts of the brain and to the spinal cord. However, when these malignant tumors are completely removed by surgery, they can better respond to radiation therapy and chemotherapy if necessary. In this way, 5-year survival has reached 50-60%. Long-term survival is not reached in malignant tumors in adults. In the last 30 years, the number of patients who survived and survived for a long time to reach adult ages increased due to evident improvements in treatment approaches.

The findings of brain tumors in childhood also differ. Tumor growth in children who have not yet thought and their the head bones are not fully attached can lead to increased intracranial pressure and abnormal head growth. Tension and out-of-the-hood can also be seen in the fontanel. Continued sleepiness, vomiting, weakness in the arm and limb, epileptic seizures may be other findings. In children, headaches that are aggravating in the morning, and then vomiting relief, are an important sign of brain tumor that every parent should take care of this.

Symptoms and Findings

Supratentorial (30-40%)

  • Cerebral hemisphere-hemiparesis, spasticity, convulsion (focal or generalized)
  • Parasellar / suprasellar-endocrinopathy (growth retardation, diabetes insipitus, pubertal disorders)
  • Hypothalamus-diencephalic syndrome (infants), development and behavioral problems
  • Optical path-vision field, acuity and color vision disorder, optic atrophy, nystagmus, tilting of the head
  • Pineal-Parinaud syndrome, sleep disorders
  • Thalamus, basal ganglion-pain, loss of sensation, memory disorders

Infratentorial (60-70%)

  • Posterior fossa-ataxia, nystagmus, dismetry
  • Brainstem - multiple cranial nerve palsies, hemiparesis, spasticity, psychic changes

Spinal (%2-5)

  • Primary intramedullary-pain, motor and sensory disorders
  • Spinal metastasis-scoliosis, sphincter disorders (bladder and rectal), reflex changes

Risk Factors

Relationship with familial diseases

  • The most common association is phakomatosis.
  • Optic glioma and meningioma in patients with neurofibromatosis type 1
  • Ependymoma, astrocytoma in patients with tuberous sclerosis
  • It is known that hemangioblastoma, pheochromocytoma and retinal tumor are more common in patients with von-Hippel-Lindau disease.
  • Brain tumors are common in Li-Fraumeni syndrome, also known as cancerous family syndrome

The relationship with ionizing radiation

  • It has been reported that secondary central nervous system tumor develops after 2-24 years in children who have received cranial radiotherapy due to previous tumor. Exposure to radiation in the prenatal period has been found to be associated with childhood CNS tumors.

Immunological factors

  • There is an increased risk of CNS tumors in organ transplantation and those receiving immunosuppressive therapy.
  • Similarly, Wiskott-Aldrich syndrome and ataxia-telangiectasia with endogenous immunosuppression are associated with CNS tumors.

Environmental factors

Diagnosis

Neurological examination

  • One of the most important steps. Especially reflexes, muscle strength, eye and mouth movements, muscle coordination and state of consciousness.

Computerised tomography

Magnetic resonance imaging (MRI)

X-ray

Angiogram

Myelogram

Lumbar puncture

  • CT indispensable diagnostic method in CNS tumors.
  • Head radiography is a method that can be used as a first step.
  • Angiography may be used to determine whether vascular tumor is embolized before craniotomy in order to exclude vascular malformation in marked hypervascular tumors (such as choroid plexus papillomas, hemangioblastoma) and reduce intraoperative bleeding.
  • MRI is a diagnostic method with many superior advantages alongside CT. The advantages of it is to better showing in Lack of artefacts caused by bone structure, ability to obtain cross-sections in many plans, absence of radiation effect, brain parenchyma and lesions in parenchyma. Disadvantages are more sensitive to motion artifacts, more shooting time than CT
  • Leptomeningeal spread; PNET may be before or after diagnosis in many children with anaplastic glioma and germinoma. In this case, cytological evaluation and spinal imaging of cerebrospinal fluid (CSF) should be performed after the operation. Cytological evaluation of CSF is often not sufficient to evaluate subarachnoid invasion in patients with PNET and germ cell tumors. Although up to 50% of these patients have normal CSF analysis, there are signs of subarachnoid disease in MRI. Therefore, both techniques are required to evaluate these patients correctly.
  • PET: 18F deoxyglucose for glucose metabolism, reflecting brain metabolism 11C-L-methionine for protein metabolism) and is a technique that is formed by the use of various agents that provide complete metabolic imaging of the brain. PET is, above all, very useful in distinguishing between recurrent or residual tumor in determining the increased metabolic rate at the onset of tm.
  • SPECT is a more accessible technique. Tm localization and degree of tm The estimate is also as useful as PET in the separation of tm and necrosis.
  • MR spectroscopy is another noninvasive method used to monitor all metabolism.

Treatment

  • Chemotherapy
  • Radiotherapy
  • Gamma-knife (stereotactic radiosurgery)
  • Ventriculoperitoneal shunt placement (palliative)

Brain tumors in children, especially cerebellum tumors, can reach serious dimensions before the diagnosis and can cause fluid circulation in the brain and cause hydrocephalus. When the diagnosis is made, the tumor should be cleaned by surgery, fluid flow should be ensured and the brain should be relieved.

Most common malignant tumors located in the cerebellum called Medulloblastoma and Ependymoma. After surgery, complete removal of these tumors and immediate success with radiation therapy and chemotherapy are increasing day by day.

Another type of malignant tumor seen in childhood is brain stem tumors (brain stem gliomas). Only 10% of these tumors can not treated by operations . In the remaining 90%, the operation is not technically possible and even biopsy is not possible. They are treated with radiotherapy and chemotherapy.

There is another childhood brain tumor, also called pilocytic astrocytoma., Seen in the cerebellum. If this tumor is considered benign and completely removed by surgery, radiation therapy and chemotherapy are not needed. It can be followed for decades without any relapses.

Other than the brain stem gliomas, all of the tumors we mentioned need urgent surgical treatment. Initially, a shunt may be inserted to relieve intracranial pressure to relieve the brain. Or the tumor can be removed by direct surgery and the brain can be relieved.