The most common types of peripheral nerve tumors are benign. The two most common types are Schwannomas, which usually occur spontaneously and sporadically but may occur as part of the Schwanommatosis Genetic Syndrome (mutation on chromosome 17) when several are present, and Neurofibromas which usually present as part of the NF1 genetic syndrome (mutation also on chromostome 17 – one of most common genetic mutations with prevalence of 1 in 3,500). Many of these tumors stop growing for very long periods of time and therefore are asymptomatic and may be observed with serial imaging studies (MRN and/or ultrasound). The symptomatic tumors usually present with pain, numbness, and/or weakness. Symptomatic and/or growing tumors should be considered for biopsy and surgical resection. Many of these tumors are can be surgically removed with minimal damage to functioning nerve fibers resulting in minimal or no loss of function. Sometimes, especially in the case of plexiform neurofibromas, resection is limited due to the intimate association of functioning nerve fibers and tumor tissue. Particularly in the setting of partially resected tumors, a postoperative MRN study with contrast should be performed which can serve as a baseline going forward. If malignancy is suspected a specialized team dealing with such challenging tumors should be consulted: further diagnostic studies often include a CT of the chest and abdomen as well as a bone scan looking for evidence of metastatic spread, a PET CT study and/or MRN with diffusion study to look for evidence of malignancy, and an open or percutaneous biopsy is often performed to confirm the diagnosis. A surgical resection combined with additional treatment such as radiotherapy is usually recommended if the tumor proves to be malignant. Again, malignant peripheral nerve tumors should be managed by a team of specialists who frequently deal with such challenging cancer problems.
- Kliot, Y. Ince, T. Tihan. M. Wilson, and M. Kliot. To grow or not to grow, that is the question. Thinking Outside The Box Section of New Developments On The Horizon Supplement. Surg Neurol Int; 4:S407-10. 2013.
- Kwok, J. Slimp, D. Born, R. Goodkin, and M. Kliot. The evaluation and management of benign peripheral nerve tumors and masses. M.S. Berger and M.D. Prados (ed.s). In: Textbook of Neuro-Oncology. Philadelphia, W.B. Saunders. 2004. pp 535-563 (Chapter 73).
E.L. Yuh, S.K. Jain, G.M Lagemann, M. Kliot, P.R. Weinstein, N.M Barbaro, and C.T. Chin. Diffusivity measurements from MR neurography differentiate benign from malignant lesions in patients presenting with peripheral neuropathy. AJNR 36: 203-209. 2015.