Malignant nerve sheath tumors of the head and neck: four case studies and review of the literature.

Malignant peripheral nerve sheath tumors (MPNST) are very uncommon neoplasms. While the incidence of these lesions is estimated to be 0.001% in a general population, they make up 5-15% of all soft tissue sarcomas in the head and neck region. We present four cases of MPNST in the head and neck. Since certain difficulties were encountered in diagnosis, the importance of clinical evaluation is emphasized. The prognosis for these tumor patients is poor in spite of improvements in diagnostic and therapeutic modalities.