Primary Malignant Peripheral Nerve Sheath Tumor of the Cauda Equina: A Case Report and Literature Review

Primary malignant peripheral nerve sheath tumors (MPNSTs) arising within the cauda equina are exceptionally rare, with only 24 cases documented in English-language literature. Due to its infrequency and aggressive behavior, no standardized treatment approach has been established. This report presents a case of primary MPNST of the cauda equina, accompanied by a comprehensive literature review, aiming to elucidate the management strategies and prognosis of this uncommon yet highly malignant tumor. A 62-year-old male was diagnosed with primary intradural MPNST and underwent gross total resection (GTR) with laminectomy along with adjunctive high-energy radiotherapy. Concurrently, we analyze existing literature concerning intradural MPNSTs. Surgical resection remains the mainstay of MPNST management, although its efficacy is limited by high recurrence rates. Despite aggressive treatment modalities, including radiotherapy and chemotherapy, primary intradural MPNSTs exhibit a propensity for leptomeningeal and systemic dissemination, contributing to a dismal overall prognosis. Notably, outcomes appear to be graver compared to MPNSTs in other anatomical locations. Primary intradural MPNSTs represent a rare and formidable clinical challenge characterized by poor prognostic outcomes. While surgical excision supplemented by adjuvant radiotherapy may offer some benefit, the need for effective targeted therapies associated with neurofibromatosis type 1 (NF1) needs to be studied more to delineate optimal treatment strategies and improve patient outcomes.