Medulloblastoma is a cancerous tumor of brain that mainly affects children. Medulloblastoma originates in the cerebellum or posterior fossa of brain. It is also called as a primitive neuroendocrine tumor, accounting for 10-20% of primary CNS neoplasms and around 40% of all posterior fossa tumors. It can take place soon after birth and into puberty. However, most tumors take place either before age ten or sometime in the late teens or early twenties. Medulloblastoma is a highly invasive embryonal neuroepithelial tumor which has tendency to disseminate throughout the CNS early in its course. Untreated tumors can easily spread to other areas of the brain and to the spine. Read out the following article to get full details about medulloblastoma including causes, symptoms, diagnosis, and treatment.
Similar tumors associated with medulloblastoma arises from the pineal region known as pineoblastomas and those tumors that arises from other CNS locations are termed as primitive neuroectodermal tumors (PNETs). In rare cases, the medulloblastoma can take place at the fourth decade of life. The condition can be treated with aggressive surgery, craniospinal radiotherapy and chemotherapy. As per estimation, more than 50% of children with medulloblastoma can be free of disease 5 years afterward. 80-90% of those without disseminated disease can be treated with the use of recent treatments.
Medulloblastomas arise in cerebellum, the area of the brain which is responsible for controlling and integrating movement. The cerebellum is situated in the back of the brain above the neck. Without the help of the cerebellum, a person could move their muscles however their movements would be ungainly and disorganized. The functions of the cerebellum can be lost and leads to uncoordinated movement, known as cerebellar ataxia. Severe symptoms, such as back pain, difficulty in walking, and the inability to control their bladder and bowel functions, signifies the spreading of cancer to the spinal cord.
Causes of Medulloblastoma:
The exact cause of medulloblastoma is unknown same as with most brain tumors and researchers are continuing to work for finding possible causes. Some symptoms that listed may also be potential underlying causes of Medulloblastoma.
The tumor can take place in relation with two rare types of genetically linked family cancer syndromes, Gorlin’s syndrome and Turcot’s syndrome. Gorlin’s syndrome is occurred due to defect in a gene known as PTC located on chromosome. Medulloblastoma and also cancers of the skin and ovary can be caused due to this defect. Turcot’s syndrome is caused by a defective gene known as APC and it can present with cancer of the intestinal tract as well as medulloblastoma. Both of these syndromes are quite uncommon and only account for a fraction of medulloblastoma cases.
Medulloblastoma as a symptom of that condition:
- Nevoid basal cell carcinoma syndrome
- Nijmegen breakage syndrome
- Microcephaly immunodeficiency lymphoreticuloma
Symptoms of Medulloblastoma:
Symptoms may be delicate and only slowly become worse, or they may take place very rapidly.
The most common symptom is headache. Brain tumors are mostly associated with headache symptoms including:
- Headache that gets worse while waking up in the morning, and then clears up within a few hours
- Double vision, weakness, or numbness
- Headaches that may get worse with coughing or exercise, or with a change in body position
- Headaches that take place while sleeping and with at least one other symptom (such as vomiting or confusion)
A patient of medulloblastoma may suffer from seizure.
Sometimes brain tumors symptoms are associated with mental changes that may include:
- Increased sleep
- Memory loss
- Impaired concentration
- Changes in personality and behavior
- Problems with reasoning
Other possible symptoms include:
- Speech difficulty
- Hearing loss, with or without dizziness
- Gradual loss of movement or feeling in an arm or leg
- Unsteadiness and problems with balance
- Unexpected vision problem (especially if it takes place with a headache), including vision loss (usually of peripheral vision) in one or both eyes, or double vision
Symptoms of medulloblastoma are same in infants, older children and teenagers. Some non-specific symptoms for example nausea and vomiting, headache, and vague visual disturbances indicate the first sign of a tumor in the cerebellum. Other more striking signs include double vision, sudden difficulty writing, and problems walking and moving that worsen over time.
Diagnosis of Medulloblastoma:
Medulloblastoma is diagnosed with both clinical observation and imaging studies. If you notice some of the signs and symptoms described above, then consult to a physician. Various specialized neurological tests have been carried out if there is any sign of a problem in the cerebellum or surrounding brain structures.
The tests include:
- Neurological examination (nerve tests): These tests will evaluate any effect of the tumor on the nervous system.
- MRI (magnetic resonance imaging) scan: This imaging study can be done to build up a detailed picture of areas of patient’s body. It is similar to a CT scan.
- CT (computerised tomography) scan: It is also imaging study which takes a series of x-rays that build up a three-dimensional picture of the inside of the body. It is painless technique and takes about 10–30 minutes.
- Biopsy: Biopsy is done for the exact diagnosis of tumor. In this test, a sample of cells from the tumor is generally taken, then looked at under a microscope.
- Lumbar puncture: A lumbar puncture is necessary to perform in some cases. In this test, a small amount of cerebral spinal fluid (CSF) can be withdrawn and then tests are carried out to see, if there are any tumour cells present.
Treatment of Medulloblastoma:
A child’s health, size and position of the tumor are the factors to be considered for the treatment of medulloblastoma. The doctor can take decision for the best type of treatment after the test results. Childhood brain tumors can occur in various stages and it is important to know these stages for the selection of treatment plans and more accurate prognosis. There are four stages defined for medulloblastoma:
- T1: The tumor having the size of less than 3 cm diameter.
- T2: The tumor has the size of greater than 3 cm in diameter and has invaded one other brain structure besides the cerebellum.
- T3: The tumor has invaded two other brain structures in addition to the cerebellum.
- T4: The tumor has spread down into the midbrain or upper spinal cord.
The treatment plan will generally be designed by a team of specialists known as a multidisciplinary team (MDT) which includes a pediatric oncologist (a doctor specializing in the treatment of childhood cancers), a pediatric neurosurgeon (a doctor specializing in childhood brain surgery), as well as a pediatric neurologist and radiation oncologist (a doctor specializing in the use of radiation to treat cancer).
- Surgery:
Surgery is the first treatment option for medulloblastoma and it is the most common treatment. The ventricles of the brain may be blocked by medulloblastoma which cause a build-up of CSF and increases the pressure within the skull. First, the pressure has to be reduced and a tube (shunt) may need to be inserted to drain off the excess fluid. Then, surgeons try to eliminate the entire tumor, although this is sometimes not possible. After completion of surgery, further treatment like radiotherapy and/or chemotherapy will be carried out depending upon whether or not the child has been placed in an “average risk” or “high risk” group.
A CT scan or MRI scan may be performed following surgery for medulloblastoma to find out how much of the tumor is left.
- Radiotherapy:
This treatment uses high-energy rays which destroys the cancer cells. Commonly, it is used after surgery to destroy any remaining malignant cells. Radiotherapy is given to the brain and spinal cord because medulloblastoma may spread through the CSF to the spinal cord. As the radiotherapy has the risk of long-term side effects, it is not given to children under the age of three whenever possible. When the child is older, radiotherapy is given in place of a course of chemotherapy.
- Chemotherapy:
Chemotherapy is the use of anti-cancer medications to destroy cancer cells. For the treatment of medulloblastoma, it may be given alone, or together with surgery and radiotherapy.
Benefits and disadvantages of treatment:
According to the stage of tumor, treatment can be given and the potential benefits will differ for each child. The treatment has been offered to cure the cancer but sometimes it is not possible and the treatment is carried out to control the cancer for a period of time.
The treatment is frequently given at an important time in development of child. Some long-term effects of treatment for medulloblastoma include growth and hormonal changes, behavioural changes and possible learning difficulties. The doctor will discuss the possible long-term effects before treatment.
Alternative and complementary therapies:
Alternative and complementary therapies are second-line therapies which are supplement to those traditional therapies with the objective of relieving symptoms. Common complementary therapies used in many types of cancer include aromatherapy, massage, meditation, music therapy, prayer, and certain forms of exercise. These therapies have the objective of decreasing anxiety and increasing a patient’s feeling of well-being.
Protein therapies, vitamins, plant extracts and natural substances such as mistletoe and shark cartilage have also been used as cancer-fighting remedies. Some alternative therapies for example Laetrile can produce dangerous side effects and have shown no anti-cancer activity in clinical trials. Before using these alternative therapies, consult doctor to ensure that the products are safe, especially for children, and do not interfere with regular cancer treatment.
Prevention:
Currently, no known ways are available to prevent medulloblastoma. Gorlin’s and Turcot’s syndrome are the genetic disorders which predisposes to medulloblastoma so people having the rare genetic disorders should be especially aware of any signs or symptoms of medulloblastomas. Children of parents having these genetic disorders should have routine screening performed by a pediatrician for any signs of a brain tumor.
Histopathology Brain, cerebellum –Medulloblastoma video from Youtube:
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all patient of medulloblastoma diagnosed…..wish u all d best!! we do wht we hv to do to get through it & pray that it all works out. take care gguys!!
i read in one research paper that the standard protocol for medulloblastoma treatment consist of two stages craniospinal and additional irradiation to the posterior fossa of the skull. this is standard procedure for local radiotherapy to the site of the tumor. there was good initial resonse to almost 83$ of patients tested.