Childhood brain tumors are the second most common tumors of all pediatric tumors after blood and bone marrow tumors and are usually located in the posterior fossa (back cavity of the brain). While brain tumors constitute 2% of all tumors in adult patients, they make up 20% in children. Brain tumors may be benign or malignant. Some tumors may be both benign and malignant depending on their grade. Most childhood brain tumors are primary tumors of the brain. Spreading (metastasis) to the brain from another part of the body is rarely seen.
These tumors are histopathologically graded between 1 and 4. While grade 1 is benign, grade 4 indicates 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. Patient complaints arising from brain tumors may vary depending on their type, location, and size.
Magnetic resonance imaging (MRI) of the brain is required to diagnose the patients. Computed tomography, radiographs, and other examinations may also be required.
The most common brain tumors encountered during childhood are medulloblastoma, astrocytoma, craniopharyngioma, ependymoma, and choroid plexus papilloma.
Although they are usually located in the posterior fossa (the back cavity of the brain), they may spread to the spinal cord and to other parts of the brain via the cerebrospinal fluid. Although these are considered malignant tumors, long-term survival may be observed in some subtypes.
Because it is situated in the back cavity of the brain, it often occludes the cerebrospinal fluid pathways and causes hydrocephalus (fluid retention in the brain), and patients may seek consultation with hydrocephalus complaints (headache, consecutive vomiting for multiple occasions etc.). Additionally, patients may also be admitted to the hospital due to complaints such as going cross-eyed and experiencing balance disorder.
These tumors may be located in both the brain and the cerebellum. They are generally benign. If they are completely removed, they are fully treated. Those which are located in the cerebellum often have a cystic component.
Those which are located in the cerebellum may show the same symptoms as medulloblastomas. If located in the brain, they may cause seizures, weakness in arms and legs, speech disorders and other types of paralyses.
Surgical therapy is the first treatment option. When the tumors are totally removed, they are generally fully treated. Radiotherapy and stereotactic radiosurgery may be performed in cases where tumors are not totally removed by surgery or in case of recurrence.
These tumors located in front of the skull, in the skull cavity behind the eyes. Although they are benign tumors, their treatment is difficult if they cannot be removed totally due to being stuck to surrounding tissues. They may recur frequently. They may have a cystic component, may be calcified and have solid parts.
Headache is one of the most common symptoms. There may be visual impairment and patients may go cross-eyed due to the proximity of the tumor in relation to the eyes and the eye nerves. Findings of hydrocephalus (headache, nausea, and vomiting), hormonal disorders and in young children, diencephalic syndrome may be encountered.
The first option is the surgical removal of the tumor. Since the tumor may be attached to the visual nerve and extremely vital and important parts of the brain, it may sometimes be impossible to remove it completely. The first goal should be to completely remove the tumor. However, if this is not possible, the maximum removable portion of the tumor is removed. Radiotherapy and stereotactic radiosurgery may be performed in cases where tumors are not totally removed by surgery or in case of recurrence.
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 may provide insight about the type and nature of the tumor, definitive diagnosis and decision is made by pathological examination of the tumor tissue under the microscope. They may spread via the cerebrospinal fluid, similar to medulloblastomas. They can go to different parts of the brain or spinal cord and grow there.
Those located in the cerebellum may show similar symptoms to medulloblastomas. Those located in the brain may cause seizures, drowsiness, weakness in arms and legs, speech disorders and other types of paralyses.
These tumors originate from the choroid plexus cells that produce 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. They often they disrupt the cerebrospinal fluid cycle and cause hydrocephalus. They may exist at birth or develop later on. They can also be diagnosed with fetal USG in the mother’s womb (intrauterine period).
Patients usually apply with signs of hydrocephalus. Headache, severe nausea and vomiting, balance disorder, visual impairment, and cross-eye are commonly encountered.
Since the recurrence rate is very low after total excision in papillomas, follow-ups can be performed in 6 months to 1-year intervals. A closer and more strict follow-up is recommended for carcinomas.
