Q: My neighbor’s son was just diagnosed with a brain tumor. How common is this? A: Tumors are abnormal cells that grow in a poorly controlled or uncontrolled fashion, and they can be benign or malignant.

Q: My neighbor’s son was just diagnosed with a brain tumor. How common is this?


A: Tumors are abnormal cells that grow in a poorly controlled or uncontrolled fashion, and they can be benign or malignant. 


Benign tumors grow where they form but do not invade the adjacent normal tissue or spread to other parts of the body like malignant tumors (cancer) can. 


Brain tumors can arise directly from abnormal brain cells (called primary brain tumors) or they can form from metastatic cancer cells spread from somewhere else in the patient. The majority of brain tumors in childhood are primary tumors, so that is what I will focus on today.


Primary childhood brain tumors can be benign or cancerous. The cancerous tumors may start out localized, but they can subsequently invade local structures or metastasize to distant sites. 


Brain tumors are the second most common cancer in children, accounting for 15 to 25 percent of childhood cancers; only leukemia (a cancer of the blood cells) is a more common cancer. In absolute numbers, brain tumors are thankfully not very common, affecting less than five out of every 100,000 kids; however, for over 3,000 kids (and families) diagnosed every year, this is still a huge issue.


Invasive brain tumors can cause problems by directly destroying healthy brain tissue, compromising the function that these cells perform. But even localized or benign tumors can cause problems just by their presence. 


The brain is surrounded by the skull. In young children, all the bones of the skull have not yet fused together (this is what allows the head to grow), so the space that the brain can occupy can ‘stretch’ a little; yet, even with this ‘flexibility,’ there is still a pretty limited amount of space. Therefore, a tumor, even a benign tumor, can cause problems if it grows enough to push or squish adjacent structures of the brain. 


The tumor can also cause increased pressure within the skull, creating swelling and/or inflammation, which in turn may compromise brain function. This increased pressure can occur directly because of the tumor’s size, or from the tumor interfering with cerebral fluid flow.


The specific symptoms caused by a brain tumor depend on which part of the brain is affected, how large the tumor is and other effects (such as swelling, increased pressure, inflammation and/or inappropriate secretion of hormones). 


Since there is often some overall inflammation caused by a brain tumor, it is not surprising that headache is the most common symptom. The “classic” description of the headache is that it gets worse upon waking in the morning but then improves over several hours; of course, this headache pattern only occurs in some patients. 


Other common symptoms include changes in mental status, behavior and even memory. Focal symptoms such as loss of one of the senses (smell, sight, hearing or speech) and even stroke-like symptoms (weakness, trouble walking) can also occur. Some patients have seizures as a complication of their tumor, and this can even be the first symptom that brings them to medical attention. 


Brain tumors are diagnosed by an imaging test (a CT or MRI), often ordered in patients whose symptoms have raised a suspicion of this condition.  Once a brain tumor is identified on an imaging test, the patient should be referred to a specialist for further testing and evaluation. The characteristics of the tumor on the imaging test, as well as its location and the symptoms the patient is having, will help decide the next appropriate steps. 


A biopsy may be done to identify the specific type of tumor and may also be crucial to help guide treatment. Blood tests and other evaluations may be required.


Depending on the location of the tumor, surgery is often considered; surgical removal is the best option for a long-term cure. Other treatments may include radiation therapy and/or chemotherapy. Newer treatments are also being developed.


A diagnosis of a brain tumor is always a serious thing, but, thankfully, treatment for this life threatening disease has improved over the years. The specific type of tumor, as well as its location, is important in the overall prognosis. 


Tumors with the potential for full surgical removal have the best chance to be cured. With today’s available treatments, about 75 percent of children diagnosed with brain tumors are still alive five years after their diagnosis, and over half will have long-term survival.


Jeff Hersh, Ph.D., M.D., F.A.A.P., F.A.C.P., F.A.A.E.P., can be reached at DrHersh@juno.com.