Functional herniated choroid plexus in brain parenchyma following VP shunt removal.

We report a 4-year-old male who presented with a blocked ventriculoperitoneal (VP) shunt inserted post excision of a WHO Grade 1 cerebellar pilocytic astrocytoma complicated post-operatively by pseudo meningocoele formation. Imaging revealed choroid plexus that had herniated along the shunt tract. Subsequent MRI showed development of cystic changes around the tract. The ectopic choroid plexus was still in continuity with the ventricular ependyma and was producing CSF in the left parietal lobe.