Peripheral primitive neuroectodermal tumor of the cerebellopontine angle.

Peripheral primitive neuroectodermal tumors are highly malignant small cell neoplasms. A 27-year-old female presented with a 6-month history of right-sided facial pain and progressive weakness of the facial muscles. She had non-pulsative tinnitus, progressive right hearing loss and facial palsy. T2-weighted MRI showed a heterogeneous hyperintense lesion invading the right internal auditory canal. Surgical removal was performed. Pathological examination showed sheets of small cells with irregular nuclei. Immunohistochemical studies demonstrated positive immunoreactivity for neuron-specific enolase, synaptophysin, chromogranin, vimentin, S-100 protein and p30-32 MIC-2 gene product. The patient was treated with chemotherapy (etoposide, vincristine, adriamycin, ifosfamide and actinomycin D) and radiotherapy. After 65 months of follow-up, the patient presented with cervical metastasis. Radical cervical dissection was performed and the patient was treated with a second course of chemotherapy. At control MRI after 29 months of follow-up the patient showed no signs of local recurrence or distant metastasis.