Central Nervous System (CNS) Tumors

Central nervous system (CNS) tumors are, after leukemia, the second most common type of cancer in children, accounting for about 20% of all pediatric malignancies. In most cases, the exact cause of childhood CNS tumors remains unknown.

One of the most common CNS tumors is medulloblastoma, which represents up to 20% of all pediatric CNS tumors. Medulloblastoma originates in the cerebellum and may spread to the brain via cerebrospinal fluid. When the tumor involves or compresses specific brain regions, it may cause dysfunction of those areas. In rare cases, the tumor can spread to bones, lungs, or other parts of the body.

Clinical symptoms depend on the child’s age and tumor location. The most frequent manifestations of medulloblastoma include: loss of balance, unsteady gait, deterioration of handwriting or slow speech, uncoordinated movements, nausea, vomiting, morning headaches or headaches relieved after vomiting, visual impairment or other ocular problems, generalized weakness, facial weakness on one side, and seizures.

For diagnosis, the main methods include detailed history-taking, neurological examination, and imaging studies such as magnetic resonance imaging (MRI) of the brain and spinal cord, as well as lumbar puncture. The most important diagnostic step is tumor biopsy, followed by histological, immunohistochemical, and molecular studies.

Treatment planning depends significantly on the tumor’s histological and molecular subtype, the extent of disease spread, and the age of the child at diagnosis. The initial treatment approach is surgery. Medulloblastoma is highly sensitive to radiotherapy, and chemotherapy is an essential component of treatment. In some cases, high-dose chemotherapy is combined with stem cell transplantation.