- See: Soft Tumor Menu

- Discussion:
    - also called malignant schwannoma or fibrosarcoma of nerve sheath;
    - extracompartmental high grade tumor that develops from sheaths (Schwann cells) of  peripheral nerves;
    - usually is a primary lesion occuring along proximal major nerve trunks,
    - tumor is usually asymptomatic until it causes neuropraxia;
    - gross inspection reveals a large fusiform mass;
    - rather than being displaced by tumor, associated nerve enters proximal pole of the tumor and exits the distal pole;
    - associated conditions:
         - neurofibromatosis:
               - neurosarcoma occassionally develops as secondary transformation of neurofibromatosis;
               - hence, look for the physical exam and radiographic characteristics of this disorder;
               - prognosis for patients with primary neurosarcoma is more favorable than for those with malignant transformation of neurofibromatosis;
               - often the transition to malignancy is heralded by new onset neurologic deficit;

- Histology:
    - fibrillar pattern is loose & have with increased cellularity;
    - multiple mitotic figures, & wavy eosinophilic pattern of neural tissue with comma shaped nuclei;
    - in an undifferentiated lesion, electron microscopic examination is needed to distinguish it from fibrosarcoma.

- Treatment:
    - wide excision w/ wide margin, if possible;
    - otherwise radical ampuatation is considered

 Malignant peripheral nerve sheath tumors: A clinicopathologic study of 120 cases.
Survival Data for Patients with Malignant Schwannoma.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, June 20, 2012 2:19 pm