Intrinsic brainstem choroid plexus papilloma. Case report.

The authors report an intrinsic brainstem lesion that was diagnosed initially as a pontine cavernoma, which finally proved to be a choroid plexus papilloma. Choroid plexus papillomas are rare tumors of the central nervous system and are usually intraventricular in location. The occurrence of this tumor in an intraparenchymal location is extremely rare, and its occurrence within the brainstem is previously unreported.