Introduction: A 14-year-old boy with no significant medical history presented to the emergency room with a sudden onset of severe headache of 1 day's duration. On admission, a non-contrast computed tomography (CT) of the head showed a posterior fossa hemorrhagic mass.
Materials and methods: He was immediately intubated and underwent placement of an external drainage tube. A magnetic resonance imaging (MRI) was performed, which showed a large hemorrhagic mass with upward cerebellar herniation.
Results: Despite aggressive measures, he deteriorated and was pronounced brain dead 2 days after admission. Pathological examination of the mass revealed a medulloblastoma with extensive neuronal and astrocytic differentiation.
Conclusion: This case represents one of the few cases of rapid, hemorrhagic expansion associated with a previously undiagnosed medulloblastoma. The topic of hemorrhage due to previously unrecognized brain tumors is discussed and the value of imaging methods used in the diagnostic assessment is emphasized.