Densely calcified atypical choroid plexus papilloma at the cerebellopontine angle in an adult.

Choroid plexus papilloma is a rare benign tumor accounting for 0.5% of all intracranial tumors. The majority of choroid plexus papillomas occur during the first 2 years of life in the ventricular system. Moreover, dense calcification of the tumor is uncommon. We report an adult case of densely calcified, atypical choroid plexus papilloma that originated from the cerebellopontine angle without connection to the forth ventricle. Because the case involves a rare combination of four features-adult, dense calcification, atypical form, and cerebellopontine angle-each characteristic associated with the choroid plexus papilloma was discussed. The finding of calcification at the cerebellopontine angle in an adult should suggest the possible presence of choroid plexus papilloma.