Skeletal Radiology

, Volume 49, Issue 1, pp 109–114 | Cite as

Extraneural perineurioma: CT and MRI imaging characteristics

  • Stephen M. BroskiEmail author
  • Laurel A. Littrell
  • Benjamin M. Howe
  • Andrew L. Folpe
  • Doris E. Wenger
Scientific Article



To examine the CT and MRI characteristics of extraneural perineuriomas.

Materials and methods

With IRB approval, our institutional imaging database was retrospectively reviewed for cases of pathologically proven extraneural perineuriomas. CT and MRI features were recorded, correlative imaging analyzed, and the electronic medical record cross-referenced.


We identified ten patients [(seven males, three females, mean age 49.4 ± 18.3 years (range, 16–70 years)]. All cases were pathologically confirmed. Nine cases were conventional soft tissue extraneural perineuriomas, including one with “reticular” features and one with histologic features of malignancy; the tenth case contained admixed Schwann cells (hybrid perineurioma/schwannoma). Six out of ten patients underwent CT and ten of ten MRI evaluation. Nine out of ten MRIs were performed with IV contrast. Five lesions were subcutaneous, four intermuscular, and one intramuscular. Mean lesion diameter was 4.3 ± 2.7 cm (range, 0.9–10.2 cm). Nine out of ten lesions were well circumscribed; one had irregular margins. On CT, five of six were hypodense and one isodense compared to skeletal muscle. Most lesions were T1 isointense (5/10) or hypointense (4/10) and T2 hyperintense (7/10) relative to skeletal muscle, and demonstrated solid enhancement (6/9). There was no evidence of muscular denervation on any MRI exam, and a nerve of origin was identified in two out of ten cases.


Extraneural perineuriomas have a distinctly different imaging appearance from intraneural perineuriomas, manifesting as rounded or ovoid soft tissue masses, without evidence of muscular denervation, and usually without an apparent nerve of origin. Because these features mimic other benign and malignant soft tissue lesions, including sarcomas, biopsy or excision is needed for definitive diagnosis.


Extraneural perineurioma CT MRI Peripheral nerve Tumor 


Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

The need for informed consent was waived by the Institutional Review Board.


  1. 1.
    Lazarus SS, Trombetta LD. Ultrastructural identification of a benign perineurial cell tumor. Cancer. 1978;41(5):1823–9.CrossRefGoogle Scholar
  2. 2.
    Macarenco RS, Ellinger F, Oliveira AM. Perineurioma: a distinctive and underrecognized peripheral nerve sheath neoplasm. Arch Pathol Lab Med. 2007;131(4):625–36.PubMedGoogle Scholar
  3. 3.
    Graadt van Roggen JF, McMenamin ME, Belchis DA, Nielsen GP, Rosenberg AE, Fletcher CD. Reticular perineurioma: a distinctive variant of soft tissue perineurioma. Am J Surg Pathol. 2001;25(4):485–93.CrossRefGoogle Scholar
  4. 4.
    Hornick JL, Fletcher CD. Soft tissue perineurioma: clinicopathologic analysis of 81 cases including those with atypical histologic features. Am J Surg Pathol. 2005;29(7):845–58.CrossRefGoogle Scholar
  5. 5.
    Fetsch JF, Miettinen M. Sclerosing perineurioma: a clinicopathologic study of 19 cases of a distinctive soft tissue lesion with a predilection for the fingers and palms of young adults. Am J Surg Pathol. 1997;21(12):1433–42.CrossRefGoogle Scholar
  6. 6.
    Giannini C, Scheithauer BW, Steinberg J, Cosgrove TJ. Intraventricular perineurioma: case report. Neurosurgery. 1998;43(6):1478–81 discussion 1481-1472.PubMedGoogle Scholar
  7. 7.
    Hornick JL, Fletcher CD. Intestinal perineuriomas: clinicopathologic definition of a new anatomic subset in a series of 10 cases. Am J Surg Pathol. 2005;29(7):859–65.CrossRefGoogle Scholar
  8. 8.
    Hirose T, Scheithauer BW, Sano T. Perineurial malignant peripheral nerve sheath tumor (MPNST): a clinicopathologic, immunohistochemical, and ultrastructural study of seven cases. Am J Surg Pathol. 1998;22(11):1368–78.CrossRefGoogle Scholar
  9. 9.
    Wilson TJ, Howe BM, Stewart SA, Spinner RJ, Amrami KK. Clinicoradiological features of intraneural perineuriomas obviate the need for tissue diagnosis. J Neurosurg. 2018;129(4):1034–40.CrossRefGoogle Scholar
  10. 10.
    Kim HJ, Yang I, Jung AY, Woo JY, Hong HS, Jeh SK, et al. Ultrasound and MR findings in sclerosing perineurioma. Skelet Radiol. 2011;40(3):353–5.CrossRefGoogle Scholar
  11. 11.
    Miyake M, Tateishi U, Maeda T, Arai Y, Seki K, Hasegawa T, et al. Sclerosing perineurioma: tumor of the hand with a short T2. Skelet Radiol. 2006;35(7):543–6.CrossRefGoogle Scholar
  12. 12.
    Miyake M, Tateishi U, Maeda T, Arai Y, Seki K, Sugimura K. Computed tomography and magnetic resonance imaging findings of soft tissue perineurioma. Radiat Med. 2008;26(6):368–71.CrossRefGoogle Scholar
  13. 13.
    Nishio J, Iwasaki H, Hayashi H, Nabeshima K, Naito M. Soft tissue perineurioma of the foot with 10q24 rearrangements: unique MRI features with histopathologic correlation. Skelet Radiol. 2014;43(7):1017–22.CrossRefGoogle Scholar
  14. 14.
    Yasumoto M, Katada Y, Matsumoto R, Adachi A, Kaneko K. Soft-tissue perineurioma of the retroperitoneum in a 63-year-old man, computed tomography and magnetic resonance imaging findings: a case report. J Med Case Rep. 2010;4:290.CrossRefGoogle Scholar
  15. 15.
    Schaefer IM, Strobel P, Thiha A, Sohns JM, Muhlfeld C, Kuffer S, et al. Soft tissue perineurioma and other unusual tumors in a patient with neurofibromatosis type 1. Int J Clin Exp Pathol. 2013;6(12):3003–8.PubMedPubMedCentralGoogle Scholar
  16. 16.
    Carter JM, Wu Y, Blessing MM, Folpe AL, Thorland EC, Spinner RJ, et al. Recurrent genomic alterations in soft tissue perineuriomas. Am J Surg Pathol. 2018;42(12):1708–14.CrossRefGoogle Scholar
  17. 17.
    Klein CJ, Wu Y, Jentoft ME, Mer G, Spinner RJ, Dyck PJ, et al. Genomic analysis reveals frequent TRAF7 mutations in intraneural perineuriomas. Ann Neurol. 2017;81(2):316–21.CrossRefGoogle Scholar
  18. 18.
    Hornick JL, Bundock EA, Fletcher CD. Hybrid schwannoma/perineurioma: clinicopathologic analysis of 42 distinctive benign nerve sheath tumors. Am J Surg Pathol. 2009;33(10):1554–61.CrossRefGoogle Scholar
  19. 19.
    Kacerovska D, Michal M, Kazakov DV. Hybrid epithelioid schwannoma/perineurioma. Am J Dermatopathol. 2016;38(7):e90–2.CrossRefGoogle Scholar
  20. 20.
    Michal M, Kazakov DV, Belousova I, Bisceglia M, Zamecnik M, Mukensnabl P. A benign neoplasm with histopathological features of both schwannoma and retiform perineurioma (benign schwannoma-perineurioma): a report of six cases of a distinctive soft tissue tumor with a predilection for the fingers. Virchows Arch. 2004;445(4):347–53.CrossRefGoogle Scholar
  21. 21.
    Mitchell A, Scheithauer BW, Doyon J, Berthiaume MJ, Isler M. Malignant perineurioma (malignant peripheral nerve sheath tumor with perineural differentiation). Clin Neuropathol. 2012;31(6):424–9.CrossRefGoogle Scholar
  22. 22.
    Rosenberg AS, Langee CL, Stevens GL, Morgan MB. Malignant peripheral nerve sheath tumor with perineurial differentiation: “malignant perineurioma”. J Cutan Pathol. 2002;29(6):362–7.CrossRefGoogle Scholar
  23. 23.
    Wilsher MJ, Mahar A, Boyle RA, Bonar SF. Malignant extraneural soft tissue perineurioma with striking microvascular proliferation. Pathology. 2015;47(1):71–5.CrossRefGoogle Scholar

Copyright information

© ISS 2019

Authors and Affiliations

  1. 1.Department of RadiologyMayo ClinicRochesterUSA
  2. 2.Department of Laboratory Medicine and PathologyMayo ClinicRochesterUSA

Personalised recommendations