Choroid plexus papillomas of the posterior fossa in adults: MR imaging and gadolinium enhancement. Report of four cases and review of the literature.

: Four cases of benign choroid plexus papillomas of the posterior fossa in adults are reported: two papillomas developed in the fourth ventricle, one in the cerebellopontine angle, and one extended from the fourth ventricle to the cerebellopontine angle. CT, MRI and surgical findings are described. The MRI characteristics on T1 and T2-weighted sequences are compared with those already published. In three cases the tumour signal observed after gadolinium enhancement was intense and homogeneous. The paramagnetic contrast agent provided direct visualization and better discrimination of papilloma location and extent.