Pediatric Brain Tumors

Childhood brain tumors are the second most common tumors of all childhood tumors after blood tumors and bone neoplasms and are usually located in the posterior fossa (posterior pit of the brain). While brain tumors constitute 2% of all tumors in adult patients, this percentage is %20 in children. Brain tumors may be benign or malignant. Some tumors may be both benign and malignant according to their degree. Most childhood brain tumors are primary tumors of the brain. Splash (metastasis) to the brain from elsewhere in the body is rarely seen.

These tumors are graded between 1 and 4 degrees histopathologically. Grade 1 is benign, 4 is the most malignant tumor. The growth rates of tumors are variable and may vary depending on their histopathological features. Malignant tumors usually grow faster. Some tumors are always malignant (glioblastoma, gliosarcoma, and others) while some tumors are considered benign tumors (pilocytic astrocytoma). Although some tumors are usually benign (meningioma, schwannoma), sometimes they may be malignant. Complaints of brain tumors in patients may vary depending on their type, location, and size.

Brain magnetic resonance imaging (MRI) is required primarily for diagnosis. Computed tomography, radiographs, and other examinations may also be required.

The most common brain tumors in childhood are medulloblastoma, astrocytoma, craniopharyngioma, ependymoma, and choroid plexus papilloma.

Medulloblastoma

Although they are usually located in the posterior fossa (the back pit of the brain), they may spread to the spinal cord and to other parts of the brain with the cerebrospinal fluid. Although it is accepted as malignant tumors, long-term survival can be observed in some of its subtypes.

Symptoms: Because it is located in the posterior pit of the brain, it often occludes the cerebrospinal fluid pathways and causes hydrocephalus (fluid retention in the brain), and patients may consult with hydrocephalus complaints (headache, continuous back-to-back, and multiple vomiting, etc.). In addition to this, the patients may apply to the hospital due to complaints such as cross-eye and balance disorder.

Treatment:

  1. Surgical: The first option is surgical treatment. If possible, the whole tumor should be removed during surgery. Other treatment options may be applied in patients who cannot receive surgical treatment.
  2. Radiotherapy: It is used to prevent recurrence after surgery or to prevent the growth and spread of the existing tumor.
  3. Chemotherapy: It is not used as a treatment alone, except in some cases. It is usually used as an add-on therapy to surgery and radiotherapy.

Astrocytoma

These tumors can be located in both the brain and the cerebellum. They are generally benign. When totally removed, they are fully cured. Those which are cerebellum located often have cystic component.

Symptoms: Those which are located in the cerebellum can give the same symptoms as medulloblastomas. When they are in the brain, seizures, weakness in the arms and legs, speech disorder and other kinds of paralysis may occur.

Treatment: Surgical therapy is the first treatment option. When the tumors are totally removed, they are generally fully cured. Radiotherapy and stereotactic radiosurgery can be performed in patients whose tumors are not surgically removed or relapsed.

Craniopharyngioma

These tumors located in the front of the head, in the skull pit behind the eyes. Although they are benign tumors, its treatment is difficult when they cannot be removed totally since it sticks to surrounding tissues. It can relapse frequently. It may have cystic component, calcified and solid parts.

Symptoms: Headache is one of the most common symptoms. There may be visual disturbances and cross-eye due to the proximity of the tumor to the eyes and the eye nerves. The symptoms of hydrocephalus (headache, nausea, and vomiting), hormonal disorders and in young children, the diencephalic syndrome may be seen.

Treatment: The first option is surgical removal of the tumor. Since the tumor may be attached to the visual nerve and vital and important parts of the brain, it may sometimes be impossible to remove the whole. The aim should be the complete removal of the tumor first. If this is not possible, however, the maximum removable part of the tumor is removed. Radiotherapy or stereotactic radiosurgery can be performed in cases that are not completely removed by surgery or in cases of recurrence.

Ependymoma

These tumors are mostly seen in the ventricle or in the areas associated with the ventricle. They may be both benign and malignant. Although radiological examinations such as MRI inform about the genus and nature of the tumor, definitive diagnosis and decision are made by pathological examination of the tumor tissue under the microscope. They may spread with cerebrospinal fluid, such as medulloblastomas. They can go to different parts of the brain or spinal cord and grow there.

Symptoms: Those located in the cerebellum may give similar symptoms with medulloblastomas. Those located in the brain may give symptoms of seizures, drowsiness, weakness in the arms and legs, speech disorders and other kinds of paralysis.

Treatment:

  1. Surgical: The first option is surgical treatment. If possible, the whole tumor should be removed during surgery. Other treatment options may be applied in patients who cannot receive surgical treatment.
  2. Radiotherapy: It is used to prevent recurrence after surgery or to prevent the growth and spread of the existing tumor.
  3. It is usually used as an add-on therapy to surgery and radiotherapy.

Choroid plexus papillomas and carcinomas

These tumors originate from the choroid plexus cells producing cerebrospinal fluid in the brain ventricles and are usually located within the ventricle. Choroid plexus papillomas are benign and choroid plexus carcinomas are malignant tumors. Most often they disrupt the cerebrospinal fluid cycle and cause hydrocephalus. It may exist at birth as well as it may develop later. It can also be diagnosed with Fetal USG in the period of the mother’s womb (intrauterine period).

Symptoms: Patients usually apply with signs of hydrocephalus. Headache, severe nausea and vomiting, balance disorder, visual impairment, and cross-eye are common.

Treatment:

  1. Surgical: It is the first option. Papillomas are cured when they are removed totally. Carcinomas may require additional treatment after surgery.
  2. Radiotherapy and stereotactic radiosurgery: It is used in carcinomas and papillomas which cannot be removed totally and with growth in their follow-ups.

Follow-up: Since the recurrence rate is very low after total excision in papillomas, 6 months to 1-year follow-up can be performed. A closer and more strict follow-up is recommended in carcinomas.