Medulloblastoma is a rapidly growing tumor of the cerebellum - the area of the brain that controls balance, posture and speech.  In children, medulloblastoma typically occurs in the connective tissue between the cerebellum and two hemispheres of the brain.  It is the most common type of brain tumor arising from immature cells, afflicting about 20% of children with brain tumors.

There are seven different classifications of medulloblastoma:

• classic medulloblastoma
• desmoplastic nodular medulloblastoma
• large-cell or anaplastic medulloblastoma
• medulloblastoma with neuroblastic or neuronal differentiation
• medulloblastoma with glial differentiation
• medullomyoblastoma
• melanotic medulloblastoma

Although the cause of medulloblastoma is unknown, significant strides are being made in understanding its biology.  For example, changes in chromosomes 17, 1, 7, 8, 9, 10q, 11 and 16 may play a part.

Symptoms of medulloblastoma include flu-like symptoms - irritability, loss of appetite, lethargy.  "Morning sickness" may be another symptom - headache, nausea, vomiting - upon waking in the morning.  Dizziness, clumsiness and staggered walking are also symptoms since the area of concern controls motor coordination.

With today's treatment options, 70% - 80% of children with average-risk medulloblastoma survive free of disease five years from diagnosis.  Children with high-risk medulloblastoma have a 60% - 65% chance of living disease-free for five years.