What is "medulloblastoma"

n. (context oncology English) A malignant type of brain tumour that originates in the cerebellum

Medulloblastoma is the most common type of pediatric malignant primary brain tumor ( cancer), originating in the part of the brain that is towards the back and the bottom, on the floor of the skull, in the cerebellum or posterior fossa.

The brain is divided into two main parts, the larger cerebrum on top and the smaller cerebellum below towards the back. They are separated by a membrane called the tentorium. Tumors that originate in the cerebellum or the surrounding region below the tentorium are therefore called infratentorial.

Historically medulloblastomas have been classified as a PNET (primitive neuroectodermal tumour), however it is now known that medulloblastoma is distinct from supratentorial PNET's and are no longer considered similar entities.

Medulloblastomas are non-invasive rapidly growing tumors that, unlike most brain tumors, spread through the cerebrospinal fluid (CSF) and frequently metastasize to different locations along the surface of the brain and spinal cord.

The cumulative relative survival rate for all age groups and histology follow-up was 60%, 52%, and 32% at 5 years, 10 years, and 20 years, respectively, with children doing better than adults.