Brain Metastasis From Malignant Peripheral Nerve Sheath Tumors.

Background: Metastatic disease is a well-known sequela of malignant peripheral nerve sheath tumors (MPNSTs). Metastic spread to the brain is unusual.

Case Description: A 56-year-old man was found to have a high grade MPNST of the sciatic nerve. Despite en-bloc excision of the sciatic nerve mass and local radiation postoperatively, he developed pathologically confirmed systemic metastases. He was found to have lung nodules and received chemotherapy 25 months after the diagnosis, and 32 months after the initial diagnosis, he presented with left leg weakness and sensory changes and was found to have a lesion of the frontal lobe for which he received palliative radiation. He developed systemic metastases and died 35 months after initial presentation. We retrospectively reviewed the charts of 179 patients treated at our institution with MPNSTs since 1994. This was the only case of a pathology proven brain metastasis, resulting in an incidence of 0.5%. Literature review revealed 21 cases. The mean age was found to be 37.5 years, and mean survival after development of a brain metastasis was 9.9 months.

Conclusions: Brain metastases from MPNSTs are very rare and represent a poor prognosis, with survival after brain metastasis reported to be approximately 10 months. Early and effective initial diagnosis and treatment of MPNSTs likely represent the best opportunity for increased overall survival.