Primary malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare in 
patients without a history of neurofibromatosis; only 18 cases have been 
reported in the English-language literature to this point. The authors report 
their experience with 1 new case of a primary MPNST. A 33-year-old woman 
presented with low-back pain radiating to the right calf that progressed over 1 
year. Magnetic resonance imaging of the spine revealed an intradural 
extramedullary lesion at the T12-L1 level. The patient was diagnosed with 
primary MPNST, underwent two surgical excisions and radiation therapy, and 
developed leptomeningeal metastases as well as brain metastases. The patient 
revisited the emergency room with sudden loss of consciousness. A brain CT scan 
displayed bilateral lateral ventricle enlargement, for which a 
ventriculoperitoneal shunt was inserted. These symptoms have not been described 
in any previous report. Primary spinal MPNST is an exceedingly rare entity, and 
the overall prognosis is very poor. To the authors' knowledge, no standard of 
care for primary spinal MPNSTs has yet been established. All 19 cases of primary 
spinal MPNSTs are reviewed, and the authors discuss their clinical, 
radiological, and therapeutic features and outcomes.