CT scan; brain tumour (papilloma), choroid plexus

CT scan of 9-year-old child showing papilloma of choroid plexus. This is a usually benign neoplasm that arises from the cuboidal epithelium of the choroid plexus and takes the form of an enlarged choroid plexus which may be associated with oversecretion of CSF. The tumour usually presents in the first decade of life with signs of increased intracranial pressure including headaches, ataxia, diplopia, and alterations of mental status. In children it is most common in the lateral ventricles and in adults it tends to arise in the fourth ventricle. Malignant transformation to choroid plexus carcinomas may rarely occur.