Neurilemmoma Treatment & Management
- Author: Ian D Dickey, MD, FRCSC; Chief Editor: Harris Gellman, MD more...
Neurilemmomas can cause a functional deficit because of local pressure on the nerve of origin. Malignant degeneration, which is extremely rare, was described by Yousem et al in 1985. Primary malignant tumors of this cell type do exist, but they are histologically distinct from neurilemmomas. In an unusual case in which resection would lead to a significant functional deficit, these benign lesions can be merely observed.
In a study assessing trends in management of unilateral vestibular schwannoma at Johns Hopkins University from 1997 through 2007, Tan et al noted an increase in cases observed with follow-up scanning (10.5% to 28.0%) and recommended for radiation (0% to 4.0%), along with a decrease in surgical cases (89.5% to 68.0%). The increased frequency of observation was significant even after age, hearing status, and tumor size were controlled for. Tan et al concluded that this trend implied changes in both provider philosophy and patient expectations.
Like most benign tumors, neurilemmomas respond well to local resection. On inspection, the nerve is usually splayed out over the lesion. The lesion is excised marginally, and the nerve fibers are spared. Interlesional resection is warranted when complete resection would result in permanent neurologic deficit. Local control is usually excellent.[9, 10, 11, 12, 13, 14]
The most common complication is initial neurapraxia; however, this neurologic deficit can be permanent, depending on the resection of neural tissue. Generally, patients tolerate resection well, with complete and rapid relief of symptoms.
Outcome and Prognosis
Recurrence is unlikely after complete resection. Patients usually have rapid and complete relief of pain, with excellent long-term results.
Rare descriptions exist of malignant change in long-standing neurilemmomas, usually in patients with an underlying diagnosis of neurofibromatosis. Malignant change is extremely rare in isolated lesions.
Kano et al evaluated tumor control and hearing preservation relating to tumor volume, imaging characteristics, and nerve and cochlear radiation dose after stereotactic radiosurgery with a Gamma Knife in patients with acoustic neuroma.
At a median of 20 months after surgery, none of the patients required further treatment. Serviceable hearing was preserved in 71% of all patients and in 89% of patients with GR (Gardner-Robertson) class I hearing. Patients who received a radiation dose less than 4.2 Gy to the central cochlea had significantly better hearing preservation of the same GR class, and all 12 patients younger than 60 years who received a cochlear radiation dose less than 4.2 Gy retained serviceable hearing at 2 years after surgery.
Roche PH, Bouvier C, Chinot O, Figarella-Branger D. Genesis and biology of vestibular schwannomas. Prog Neurol Surg. 2008. 21:24-31. [Medline].
Guerrissi JO. Solitary benign schwannomas in major nerve systems of the head and neck. J Craniofac Surg. 2009 May. 20(3):957-61. [Medline].
Bakar B, Sumer MM, Cila A, Tekkok IH. An extreme lateral lumbar disc herniation mimicking L4 schwannoma. Acta Neurol Belg. 2009 Jun. 109(2):155-8. [Medline].
Ichinose T, Takami T, Yamamoto N, Tsuyuguchi N, Ohata K. Intratumoral hemorrhage of spinal schwannoma of the cauda equina manifesting as acute paraparesis--case report. Neurol Med Chir (Tokyo). 2009 Jun. 49(6):255-7. [Medline].
Fortnum H, O'Neill C, Taylor R, Lenthall R, Nikolopoulos T, Lightfoot G, et al. The role of magnetic resonance imaging in the identification of suspected acoustic neuroma: a systematic review of clinical and cost effectiveness and natural history. Health Technol Assess. 2009 Mar. 13(18):iii-iv, ix-xi, 1-154. [Medline].
Wu S, Liu G, Tu R. Value of ultrasonography in neurilemmoma diagnosis: the role of round shape morphology. Med Ultrason. 2012 Sep. 14(3):192-6. [Medline].
Yousem SA, Colby TV, Urich H. Malignant epithelioid schwannoma arising in a benign schwannoma. A case report. Cancer. 1985 Jun 15. 55(12):2799-803. [Medline].
Tan M, Myrie OA, Lin FR, Niparko JK, Minor LB, Tamargo RJ, et al. Trends in the management of vestibular schwannomas at Johns Hopkins 1997-2007. Laryngoscope. 2010 Jan. 120(1):144-9. [Medline].
Kida Y, Yoshimoto M, Hasegawa T. Radiosurgery for facial schwannoma. J Neurosurg. 2007 Jan. 106(1):24-9. [Medline].
Rutten I, Baumert BG, Seidel L, et al. Long-term follow-up reveals low toxicity of radiosurgery for vestibular schwannoma. Radiother Oncol. 2007 Jan. 82(1):83-9. [Medline].
Sade B, Mohr G, Dufour JJ. Vascular complications of vestibular schwannoma surgery: a comparison of the suboccipital retrosigmoid and translabyrinthine approaches. J Neurosurg. 2006 Aug. 105(2):200-4. [Medline].
Strauss C, Prell J, Rampp S, et al. Split facial nerve course in vestibular schwannomas. J Neurosurg. 2006 Nov. 105(5):698-705. [Medline].
Kondziolka D, Lunsford LD. Future perspectives in acoustic neuroma management. Prog Neurol Surg. 2008. 21:247-54. [Medline].
Pillai P, Sammet S, Ammirati M. Image-guided, endoscopic-assisted drilling and exposure of the whole length of the internal auditory canal and its fundus with preservation of the integrity of the labyrinth using a retrosigmoid approach: a laboratory investigation. Neurosurgery. 2009 Dec. 65(6 Suppl):53-9; discussion 59. [Medline].
Kano H, Kondziolka D, Khan A, Flickinger JC, Lunsford LD. Predictors of hearing preservation after stereotactic radiosurgery for acoustic neuroma. J Neurosurg. 2009 Oct. 111(4):863-73. [Medline].
Beggs I. Pictorial review: imaging of peripheral nerve tumours. Clin Radiol. 1997 Jan. 52(1):8-17. [Medline].
Belding RH. Neurilemoma of the lateral plantar nerve producing tarsal tunnel syndrome: a case report. Foot Ankle. 1993 Jun. 14(5):289-91. [Medline].
Campanacci M. Bone and Soft Tissue Tumors: Clinical Features, Imaging, Pathology and Treatment. 2nd ed. New York, NY: Springer-Verlag; 1999.
Cerofolini E, Landi A, DeSantis G, et al. MR of benign peripheral nerve sheath tumors. J Comput Assist Tomogr. 1991 Jul-Aug. 15(4):593-7. [Medline].
Idler RS. Benign and malignant nerve tumors. Hand Clin. 1995 May. 11(2):203-9. [Medline].
Mikami Y, Hidaka T, Akisada T, et al. Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study. Pathol Int. 2000 Feb. 50(2):156-61. [Medline].
Stull MA, Moser RP, Kransdorf MJ, et al. Magnetic resonance appearance of peripheral nerve sheath tumors. Skeletal Radiol. 1991. 20(1):9-14. [Medline].
Woodruff JM, Selig AM, Crowley K, et al. Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor. Am J Surg Pathol. 1994 Sep. 18(9):882-95. [Medline].