From the Guidelines
Diagnosis and treatment of nerve sheath tumors (neurofibromas) should be approached with caution, as they can be benign or malignant, with malignant peripheral nerve sheath tumors (MPNSTs) being a rare but aggressive type of sarcoma.
Diagnosis
- Clinical suspicion, such as pain, rapid growth, neurologic symptoms, and deep or truncal location of the tumor, is crucial for early detection of MPNSTs 1
- Imaging modalities like MRI, particularly whole-body MRI (WB-MRI), can help detect and monitor neurofibromas and MPNSTs 1
- The use of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and PET/CT can aid in diagnosing MPNSTs, with a sensitivity of 0.89 and a specificity of 0.95 1
Treatment
- Surgery remains the cornerstone of treatment for high-grade MPNSTs, aiming to achieve clear margins 1
- Adjuvant chemotherapy and radiation may have a role in some MPNST patients with non-metastatic disease, although more research is needed to confirm their benefits 1
- For advanced and metastatic MPNST, the prognosis is poor, and treatment options are limited, with response rates to doxorubicin plus ifosfamide being around 21% 1
- Targeted therapies, such as MEK inhibitors (e.g., selumetinib and trametinib) and receptor tyrosine kinase inhibitors (e.g., cabozantinib), have shown promise in managing symptomatic, inoperable neurofibromas in patients with neurofibromatosis type 1 (NF1) 1
Management
- Close monitoring and regular follow-up are essential for patients with neurofibromas, as they can transform into MPNSTs 1
- A multidisciplinary approach, involving radiologists, surgeons, oncologists, and other specialists, is necessary for the optimal management of nerve sheath tumors 1
From the Research
Diagnosis of Nerve Sheath Tumors
- The diagnosis of nerve sheath tumors is made based on histological and pathological findings, with imaging studies helping to orient the diagnosis 2.
- Magnetic resonance imaging (MRI) is the diagnostic study of choice for nerve sheath tumors 3.
- The diagnosis of malignant peripheral nerve sheath tumors (MPNSTs) can be challenging, with no defined diagnosis criteria and no established therapeutic strategies 2.
- A preexisting knowledge of the clinical situation is more likely to lead to a correct diagnosis of MPNSTs 2.
Treatment of Nerve Sheath Tumors
- The mainstay of treatment for nerve sheath tumors is radical surgical resection, with adjuvant radiotherapy for MPNSTs 2, 4.
- Complete resection of benign nerve sheath tumors is the goal of surgical intervention, resulting in cure 3.
- For neurofibromas, surgical treatment involves either resection of the tumor and immediate reconstruction with a peripheral nerve graft, or subtotal removal and follow-up 4.
- In the case of MPNSTs, a wide surgical excision is advocated, with the resectability depending on the location of the tumors 4.
Treatment Options for Specific Types of Nerve Sheath Tumors
- For MPNSTs associated with neurofibromatosis type 1 (NF-1), treatment options include surgery, chemotherapy, and adjuvant radiotherapy, although the role and efficacy of chemotherapy and radiotherapy are unclear 5.
- For spinal nerve sheath tumors, treatment options include surgical resection, with the goal of preserving neurologic function 3, 4.
- For MPNSTs, treatment should be managed by a multidisciplinary team of neurosurgeons, radiologists, and oncologists 4.