Primitive neuroectodermal tumor (PNET) extending into the cerebellopontine angle: case report.

The most common primary tumors of the cerebellopontine angle are growths of the 8th cranial nerve. The occurrence of other tumors in this area is very rare and may cause neuroradiological misinterpretation. We report the findings in a 37-year-old male patient suffering from a primitive neuroectodermal tumor (PNET) extending from the latero-basilar cerebellar hemisphere into the cerebellopontine angle (CPA) and causing cerebellar dysfunction as well as symptoms of typical cerebellopontine angle lesions. Differential diagnosis of tumors found in this area is given as well as a histological description of the tumor along with immunohistochemical findings and aspects of possible prognostic relevance.