Malignant peripheral nerve sheath tumor of the vestibulocochlear nerve and brainstem: multimodality treatment with survival of 27 months. A case report and review of the literature.

BACKGROUND AND IMPORTANCE Malignant peripheral nerve sheath tumors are the most common malignant mesenchymal tumors of soft tissues, but they are very rare when found to arise from a cranial nerve and when not in association with neurofibromatosis. These tumors are highly malignant and carry a poor prognosis with survival usually less than 6 months. CLINICAL PRESENTATION The authors report the case of a 23-year-old female with no history of phakomatoses, previous irradiation, or known genetic disorders, who presented with a malignant peripheral nerve sheath tumor of the vestibulocochlear nerve and brainstem. Multiple staged skull base approaches were carried out with maximal possible resection. Adjunctive therapies including standard radiation therapy, intensity-modulated radiation therapy, and stereotactic gamma knife radiosurgery were used with an ultimate patient survival of 27 months. CONCLUSION To our knowledge, this is the first report describing a patient with a malignant peripheral nerve sheath tumor of the vestibulocochlear nerve and brainstem treated with staged surgical approaches in conjunction with multiple forms of radiotherapy and having a significant survival of more than 2 years.