Pilocytic astrocytomas (PAs) are benign glial tumors and one of the most common 
childhood posterior fossa tumors. Spontaneous intratumoral hemorrhage in PAs 
occurs occasionally, in about 8-20% of cases. Cerebellar hemorrhages in 
pediatric population are rare and mainly due to head injuries, rupture of 
vascular malformations, infections, or hematological diseases. We have 
investigated the still controversial and unclear pathophysiology underlying 
intratumoral hemorrhage in PAs. Bleeding in low-grade tumors might be related to 
structural abnormalities and specific angio-architecture of tumor vessels, such 
as degenerative mural hyalinization, "glomeruloid" endothelial proliferation, 
presence of encased micro-aneurysms, and glioma-induced neoangiogenesis. The 
acute hemorrhagic presentation of cerebellar PA in childhood although extremely 
uncommon is of critical clinical importance and necessitates promptly treatment. 
We described a case of hemorrhagic cerebellar PA in a 9-year-old child and 
reviewed the English-language literature that reported spontaneous hemorrhagic 
histologically proven cerebellar PA in pediatric patients (0-18 years). 
According to our analysis, the mortality was not related to symptom onset, tumor 
location, hemorrhage distribution, presence of acute hydrocephalous, and timing 
of surgery, while the GCS at hospital admission resulted to be the only 
statistically significant prognostic factor affecting survival outcome. The 
abrupt onset of signs and symptoms of acute hydrocephalous and consequent raised 
intracranial pressure are life-threatening conditions, which need emergent 
medical and neurosurgical treatments. At a later time, the identification of 
posterior fossa hemorrhage etiology is crucial to select the appropriate 
treatment and address the surgical strategy, optimizing the postoperative 
results.