• Solitary lesion (90%) or occurring in von Recklinghausen’s disease (10%) of Schwann cells
  • Types
  • Storiform perineural fibroma
  • Pacinian neurofibroma
  • Epithelioid neurofibroma
  • Pigmented neurofibroma —melanocytic differentiation (both Schwann cells and melanocyte of neural crest origin)


  • Large lesions (>4cm) may not be benign and require resection after workup
  • Commonly associated with neurofibromatosis
  • ~5% of benign soft tissue tumors


  • M=F to slight M preponderance reported
  • Most patients 20-30 years of age
  • Most superficial dermal or subcutaneous lesions
  • Solitary spinal neurofibroma may present with radicular sxs
  • Has been reported occurring in the same nerve trunk as a neurilemoma


  • MRI best demonstrates ovoid lesion that is well circumscribed
  • Spinal lesion x-ray may show pedicle or vertebral body erosion, ? interpedicular distance, laminae(e) distortion, neural foramenal enlargement
  • Myelography: "amputation" of nerve root with a filling defect
  • US: well-defined hypoechoic lesion
  • CT: intra- and extraspinal "hour-glass" appearance
    • Hypodense to muscle
    • Enhances with contrast
  • MRI:
    • T1-weighted images show intensity of lesion slightly higher than muscle
    • T2-weighted images show signal (peripheral > central) with bright non-uniform gadolinium DPTA enhancement (peripheral > central)("target sign")


  • Grayish-white to yellow-brown
  • Not encapsulated (unlike neurilemmoma)
  • May be myxomatous to hard and rubbery


  • Lack two distinct zones (unlike neurilemmoma)
  • Interlacing elongated cell bundles with wavy nuclei of varying cellularity
  • Arrangement of cells in fascicles, whorls, or storiform
  • EM
    • Schwann cells with a large nuclei, little cytoplasm, and pronounced basal lamina
    • Fibroblast-like cells and mast cells also are present


  • Myxoma
  • Neurilemoma (S-100 usually negative, unlike neurilemoma)


  • Simple excision
  • Residual numbness should be warned about, esp in digital locations (where grafting may be appropriate)
  • Risk of malignant degeneration small, esp in solitary lesions



    • (Nerve sheath myxoma)
    • Involve head, neck, and shoulder, arising in childhood
    • Usually superficial
    • Lobular areas of myxoid material with neural cell differentiation demonstrated by EM


Bashear H, Rabin F, Basheer H, El-Helw K: Neurofibromas of digital nerves. J Hand Surg 22B:61-3,1997.

Cavallazzi RM, Spreafico G, Galli C, Raimondi P: A neurilemmoma and a neurofibroma in the same nerve trunk. J Hand Surg 13B:96,1988.

Cerofalini E, Landi A, De Santis G, Maiorana A, Canossi G, Romagnoli R: MR of benign peripheral nerve sheath tumors. J Comp Assist Tomog 15:593-7,1991.

Donner TR, Voorhies RM, Kline DG: Neural sheath tumors of major nerves. J Neurosurg 81:362-73,1994.

Enzinger FM, Weiss SW: Benign Tumors of Peripheral Nerves. In Soft Tissue Tumors FM Enzinger and SW Weiss (Eds), C.V. Mosby Co., St. Louis (3rd ed) 1995, pp 821-88.

Gouliamos AD, Kontogiannis DS, Androulidakis EJ, Kalovidouris AE, Vlahos LJ, Papavasiliou CG: Spinal neurilemmomas and neurofibromas: central dot signal in postgadolinium MRI. J Comput Assist Tomogr 17:446-8,1993.

Hems TEJ, Burge PD, Wilson DJ: The role of magnetic resonance imaging in the management of peripheral nerve tumours. J Hand Surg 22B:57-60,1997.

Holdsworth BJ: Nerve tumours in the upper limb. A clinical review. J Hand Surg 10B:236-8,1985.

Kehoe NJS, Reid RP: Solitary benign peripheral-nerve tumours. Review of 32 years’ experience. J Bone Joint Surg 77B:497-500,1995.

Lin J, Martel W: Cross-sectional imaging of peripheral nerve sheath tumors: characteristic signs on CT, MR imaging, and sonography. AJR 176:75-82,2001.

Lusk MD, Kline DG, Garcia CA: Tumors of the brachial plexus. Neurosurgery 21:439-53,1987.

Nagey L, McCabe SJ, Wolff TW: A case of neurofibroma of the palmar cutaneous branch of the median nerve. J Hand Surg 15B:489-90,1990.

Ogose A, Hotta T, Morita T, Yamamura S, Hosaka N, Kobayashi H, Hirata Y: Tumors of peripheral nerves: correlation of symptoms, clinical signs, imaging features, and histologic diagnosis. Skeletal Radiol 28:183-8,1999.

Sanguinetti C, Specchia N, Gigante A, DePalma L, Greco F: Clinical and pathological aspects of solitary spinal neurofibroma. J Bone Joint Surg 75B:141-7,1993.

Stull MA, Moser RP, Kransdorf MJ, Bogumill GP, Nelson MC: Magnetic resonance appearance of peripheral nerve sheath tumors. Skeletal Radiol 20:9-14,1991.

Suh J-S, Abezona P, Galloway HR, Everson LE, Griffiths HJ: Peripheral (extracranial) nerve tumors: correlation of MR imaging and histologic findings. Radiology 183:341-6,1992.

Varma DG, Moulopoulos A, Sara AS, : MR imaging of extracranial nerve sheath tumors. J Comput Assist Tomogr 16:448-53,1992.