Teaching Neuro Images : Acquired Chiari malformation with syringohydromyelia caused by posterior fossa tumor

A 28-year-old man was admitted due to progressive headache and blurred vision. Neurologic examination showed bilateral papilledema. Brain MRI showed a cystic posterior fossa tumor compressing the fourth ventricle with tonsillar herniation and cervical syringohydromyelia (figure 1). The tumor was removed through a suboccipital craniectomy and pilocytic astrocytoma was diagnosed histologically. One month later, his symptoms had improved with shrinkage …