They are formed from abnormal brain cells at a very early stage in development. Medulloblastomas are usually found in children or young adults between the ages of 21 and 40 years.
Nad moodustuvad ebanormaalsed ajurakke väga varajases staadiumis areng. Medulloblastomas on tavaliselt leitud lastel ja noortel täiskasvanutel vanuses 21 ja 40 aastat.