High grade gliomas, atypical teratoid/rhabdoid tumor, and choroid plexus papilloma of the fourth ventricle are less frequent.
Because of the different treatment options and variability in long-term outcome, an accurate and specific diagnosis is mandatory 1).
Cerebellar pilocytic astrocytoma: most common
Medulloblastoma: (also known as posterior fossa PNET)
Atypical teratoid rhabdoid tumor (AT/RT)
Hemangioblastoma (uncommon except in patients with vHL)
A quick and handy mnemonic for posterior fossa tumours in children is BEAM.
Although it is true that posterior fossa tumours are much more common in children than in adults the distribution does vary with age:
4 to 10 years of age: infratentorial > supratentorial
10 to early adult hood: infratentorial = supratentorial
adults: supratentorial > infratentorial
Imaging plays a major role in the comprehensive assessment of posterior fossa tumors in children (PFTC). The objective of Kerleroux et al. was to propose a global method relying on the combined analysis of radiological, clinical and epidemiological criteria, (taking into account the child's age and the topography of the lesion) in order to improve our histological approach in imaging, helping the management and approach for surgeons in providing information to the patients' parents. Infratentorial tumors are the most frequent in children, representing mainly medulloblastoma, pilocytic astrocytoma and brainstem glioma. Pre-surgical identification of the tumor type and its aggressiveness could be improved by the combined analysis of key imaging features with epidemiologic data 2).
A developmental and anatomic approach to the posterior fossa tumors in children (together with diffusion imaging data) provides a reliable pre-surgical identification of the tumor and of its aggressiveness 3).
Over the last decades, the mortality rate of children with posterior fossa tumors has gradually decreased. While survival has been the primary objective in most reports, quality of survival increasingly appears to be an important indicator of a successful outcome. Children with a PF tumor can sustain damage to the cerebellum and other brain structures from the tumor itself, concomitant hydrocephalus, the consequences of treatment (surgery, chemotherapy, radiotherapy), or a combination of these factors. Together, these contribute to long-term sequelae in physical functioning, neuropsychological late outcomes (including academic outcome, working memory, perception and estimation of time, and selective attention, long-term neuromotor speech deficits, and executive functioning). Long-term quality of life can also be affected by endocrinological complication or the occurrence of secondary tumors. A significant proportion of survivors of PF tumors require long-term special education services and have reduced rates of high school graduation and employment. Interventions to improve neuropsychological functioning in childhood PF tumor survivors include (1) pharmacological interventions (such as methylphenidate, modafinil, or donepezil), (2) cognitive remediation, and (3) home-based computerized cognitive training. In order to achieve the best possible outcome for survivors, and ultimately minimize long-term complications, new interventions must be developed to prevent and ameliorate the neuro-toxic effects experienced by these children 4).
Age at diagnosis and treatment factors are important variables that affect the outcomes of the survivors 5).