Intracranial metastasis from a malignant peripheral nerve sheath tumor in a patient with neurofibromatosis type 1: A case study and literature review

Introduction: Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are a rare type of soft tissue sarcoma. While these tumors often metastasize, intracranial metastases of MPNSTs have only been rarely noted. Methods: Using Pubmed, Google Scholar, and Science Direct we conducted a systematic review of the literature to identify all reported cases of MPNSTs with metastases to the brain since the inception of these databases through January 2020. Data were extracted and data analysis was completed using python statistical packages. Results: Only 26 cases (including present study) of MPNSTs resulting in intracranial metastases have been reported in the literature. Eight of these 26 cases occurred in patients who were previously diagnosed with Neurofibromatosis Type 1 (NF1). Additionally, one patient had been previously diagnosed with Neurofibromatosis Type 2 (NF2). The average reported time from diagnosis of a MPNST to the time of diagnosis with intracranial metastasis was 36 months, with a median time of 14 months. The average reported survival time for patients after being diagnosed with intracranial metastasis was 5.9 months. The cases that utilized a combination of therapeutic intervention including surgical resection, radiotherapy and chemotherapy saw the greatest improvement of survival times. Conclusion: MPNSTs with brain metastases are extremely rare and have a poor prognosis with a 6 months median survival after metastasis. While combination therapy is indicated, further studies on treatment are needed to determine survival benefits. Early and effective initial diagnosis of MPNST before brain metastases occurs is likely to give the best chance of increased overall survival.