Definition and Diagnosis

A MPNST of the leg (asterisks, multiple images of the same tumor) in a patient with neurofibromatosis.

MPNSTs are aggressive tumors that arise from peripheral nerves. They may recur after removal and even spread to the lungs and liver. They occur spontaneously, but also arise from known neurofibromas in patients with neurofibromatosis. Although MRI defines the tumor, imaging usually cannot determine if the tumor is malignant.

Treatment Options

In general, when nerve sheath tumors are symptomatic or progressively enlarging, they are removed completely with surgery. If the subsequent pathology reveals malignancy, then chemotherapy, radiation, and even re-operation may be recommended.