There are many different types of pediatric brain tumors, which are the second most common type of cancer in children. Diagnosis for this rare brain tumors is particularly hard because the symptoms and signs of brain tumors in children are general and biopsies can often be misdiagnosed if a health professional is not experienced .
In this article, the rare brain tumors brainstem gliomas, choroid plexus tumor, primitive neuroectodermal tumors, and craniopharyngioma are discussed. You will find more information about common brain tumors in children here.
Brainstem gliomas refer to tumors that form in the brain stem of patients, which is the lowest part of the brain that is connected to the spinal cord and controls vital functions such as breathing and heart rate .
Brainstem gliomas comprise 10% of all pediatric brain tumors. The survival rate of children who develop brainstem gliomas is very low, and a minority of these patients are alive for three years after diagnosis. The average age at which patients develop this tumor is the age of 6 .
There are two types of brainstem gliomas in children:
- focal glioma and
- diffuse intrinsic pontine glioma (DIPG)
Focal glioma is the more benign tumor that is slow growing and is localized to one area of the brain stem, which makes it easier to treat and therefore has a better prognosis.
Diffuse intrinsic pontine glioma (DIPG) has a worse prognosis as it is a higher grade tumor that grows rapidly and spreads all over the brain stem, which makes it much harder to treat.
However, prognosis also depends on the age of the child. If the patient is less than three years of age then the chances of recovery are better than in children that are older. While most cases of brainstem gliomas are sporadic, there are some factors that predispose children to developing this tumor such as the genetic disorder neurofibromatosis type 1 .
Choroid Plexus Tumor
Choroid plexus tumors are extremely rare and divided into three categories according to the grade of the cancer:
- grade I tumor is called choroid plexus papilloma,
- grade II is atypical choroid plexus papilloma and
- grade III is choroid plexus carcinoma.
As these tumors are rare, the incidence of chronic plexus tumors is 0.3 cases per million people. While this tumor can occur at any age, it peaks in the teenage years .
Grade I tumors are five times more common than grade III tumors, with 90% of all choroid plexus tumors being grade I choroid plexus papilloma. Most choroid plexus tumors occur randomly, but there are some genetic factors that can lead to the development of this tumor. Patients with:
- Aircardi syndrome,
- Down’s syndrome,
- von Hippel-Lindau disease and
- neurofibromatosis type 2
are more likely to develop this tutor .
The prognosis for these tumors depends largely on the ability to remove the tumor as well as the grade of the tumor. Therefore, surgical resection is the most common first-line therapy for these patients. Grade I choroid plexus tumors can be treated by surgical removal and even if the tumor occurs again the prognosis is still good with a 5-year survival of 80-100%. Some of these grade I tumors do become malignant but most of them stay benign.
Grade III choroid plexus tumors are more aggressive and have a tendency to metastasize or recur. In addition, the survival rate of grade III tumors is 50% of that of grade I tumours .
Primitive Neuroectodermal Tumors (PNETs)
There are three characterizations of PNETs called
- Central Nervous System-PNETS (CNS-PNETs),
- neuroblastoma and
These are very rare tumors that have a very low incidence (about 2.9 cases per million), which may be due to misdiagnosis or underdiagnosis of this tumor.
These tumors are rare in African Americans and Asians and occur most commonly in white and Hispanic patients. The primary treatment for children with primitive neuroectodermal tumors is a complete removal of the tumor. However, in some cases, if the tumor has metastasized or if it infringes on important and sensitive areas of the brain, the tumor cannot be removed. Chemotherapy for treatment of brain tumors in children and radiation for treatment of brain tumors in children are also necessary for treatment in conjunction with surgery, with the treatments being personalized to each patient depending on age, location and level of metastasis .
Craniopharyngioma is a benign tumor that develops in the pituitary gland. This tumor occurs most commonly in patients between five to ten years of age, though some adults can also develop this tumor. The incidence of this tumor is 1.4 cases per million children .
In addition to the normal symptoms that occur with the development of brain tumors, the location of this type of tumor also causes hormonal imbalances which can manifest as:
- thirst and
- as well as impaired growth.
Sometimes, vision impairment can also develop if the tumor affects the optic nerve.
These issues can sometimes be long-term and may even be aggravated by surgery. However, surgery is still the main first-line treatment for this tumor along with radiation treatment for tumors that are unable to be removed .