Medulloblastomas

Medulloblastomas is a genetic disease that originates from changes in the DNA of brain cells. These changes develop highly malignant invasive tumors in the cerebellum or posterior fossa of the brain. Also referred to as infratentorial tumors because of the location of where the tumors are develop. The tentorium is a thick membrane that separates the cerebral hemispheres and the cerebellum of the brain. Medulloblastomas are most commonly diagnosed in children and are rarely diagnosed in adults. Of all the primary brain tumors meaning that they originate in the brain, Medulloblastomas only account for less than 2%. More than 70 % are diagnosed in children under age 10. Very few instances occur in infants under 1.

Scientist have yet to discover what triggers these tumors but are progressively learning it's biology. Changes in the genes and chromosomes have been noted as an important role in the development of these tumors. One- third of all pediatric medulloblastomas contain a change on chromosome 17. Similar changes on chromosomes 1,7,8,9,10, 11 and 16 may also play a part. Medulloblastomas is a genetic pathology that occurs through changes in the DNA of brain cells and should not be mistaken as an inherited disease.

Flu- like symptoms experienced by patients diagnosed with this tumor-lethargy, irritable and loss of appetite- are often gone undetected in the early stages because they are non-specific. Abnormal head size and irritable can be the first signs in infants. Older children and adults usually experience vomiting and headaches first thing in the morning. As time passes and the pressure in the brain increases from fluid accumulation (hydrocephalus), the symptoms become more severe.

A MRI with and with out contrast is usually done to locate and receive a thorough diagnosis. The dye will be concentrated in abnormal tissues making the tumor appear much brighter than normal tissues in a T1 weighted contrast image . The tumor will be attempted to be removed surgically followed by crainospinal radiation or chemotherapy.

References:

Robert Packer(2010) Medulloblastoma. Retrieved Feburary 3, 2010 from http://www.childhoodbraintumor.org/index.php/brain-tumor-types-and-imaging/34-brain-tumor-types-and-imaging/97-medulloblastoma.html

http://cancer.emedtv.com/medulloblastoma/medulloblastoma.html

http://www.abta.org/sitefiles/sitePages/D3A2C571CD0CDE16C0FFE57607F22A65.pdf