Perineural Tumor Spread

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Perineural spread (PNS) refers to the extent of tumor cells or other nonneoplastic lesions along the tissues of the nerve sheath, its overall incidence ranges from 2.5% to 5%. PNS is more frequently associated with carcinoma arising from minor or major salivary glands (more often adenoid cystic carcinoma), mucosal or cutaneous squamous cell carcinoma, basal cell carcinoma, melanoma, lymphoma, and sarcoma. Although PNS was previously associated with worsening prognosis, increasing evidence shows that cure is possible. Therefore, radiologists must be aware of the relevant cranial nerve anatomy and thoroughly scrutinize not only the nerves close to the primary tumor site but also the whole neural pathways that can be accessed by PNS. Equally critical is knowledge of the radiologic appearance of perineural tumor extension and the best imaging strategies to detect PNS.

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Incidence, epidemiology, and most frequent malignant tumors showing perineural spread

Overall, the incidence of PNS ranges from 2.5% to 5%.6 Although it may occur with any head and neck malignancy, PNS is more frequently associated with carcinoma arising from minor or major salivary glands (more often adenoid cystic carcinoma [ACC]), mucosal or cutaneous squamous cell carcinoma (SCC), basal cell carcinoma (BCC), melanoma, lymphoma, and sarcoma.

PNS along a major (named) nerve has been observed in up to 28% of ACC arising from major or minor salivary and nonsalivary glands.7

Neural pathways relevant for perineural spread

In most cases the peripheral branches of the second (V2) or third division (V3) of the trigeminal nerve and the descending branch of the facial nerve serve as conduits for perineural tumor spread into the skull base.

Preexisting neural pathways, such as the vidian nerve, greater superficial petrosal nerve (GSPN), and auriculotemporal nerve (ATN), account for neoplastic dissemination from trigeminal branches to those of the facial nerve (and vice versa).15, 16, 17 Less frequently, the ophthalmic

Normal aspect of cranial nerves through cisterns, foramina, and fissures, and outside the skull base

On cross-sectional imaging, the detectability of normal cranial nerves and their major branches depends on their size and the difference in signal intensity between nerve and surrounding structures. Generally, nerve segments traveling through cisterns are more easily shown by T2-weighted MR sequences, which enhance the difference in signal intensity between CSF and nerves. High-resolution three-dimensional T2-weighted fast spin-echo (SE) sequences (FSE or FASE) or the three-dimensional

Imaging findings of perineural spread

The single nerve fibers, axons and their covering derived from Schwann cells, are separated by loose vascular connective tissue and extracellular fluid (endoneurium). Several nerve fibers and endoneurium are bundled into fascicles, each one surrounded by a dense connective sheath (perineurium). The perineurium and the tight junctions between the endothelial cells of the endoneurial capillaries isolate the extracellular endoneurial fluid from the general extracellular space.42 Large nerves

References (60)

  • I.M. Ziyal et al.

    The trigeminal nerve and ganglion: an anatomical, histological, and radiological study addressing the transtrigeminal approach

    Surg Neurol

    (2004)
  • W.M. Mendenhall et al.

    Carcinoma of the skin of the head and neck with perineural invasion

    Head Neck

    (2002)
  • T.J. Galloway et al.

    Impact of radiographic findings on prognosis for skin carcinoma with clinical perineural invasion

    Cancer

    (2005)
  • H.D. Curtin

    Detection of perineural spread: fat suppression versus no fat suppression

    AJNR Am J Neuroradiol

    (2004)
  • B.Z. Fowler et al.

    Perineural spread of cutaneous malignancy to the brain: a review of the literature and five patients treated with stereotactic radiotherapy

    Cancer

    (2005)
  • J.A. Hutcheson et al.

    Neural cell adhesion molecule expression in adenoid cystic carcinoma of the head and neck

    Laryngoscope

    (2000)
  • S.J. Miknyoczki et al.

    Neurotrophin-Trk receptor interactions in neoplasia: a possible role in interstitial and perineural invasion in ductal pancreatic cancer

    Crit Rev Oncog

    (1996)
  • P. Kalina et al.

    Perineural extension of facial melanoma

    Neuroradiology

    (2005)
  • P.C. Chang et al.

    Perineural spread of malignant melanoma of the head and neck: clinical and imaging features

    AJNR Am J Neuroradiol

    (2004)
  • A. Blandino et al.

    CT and MR findings in neoplastic perineural spread along the vidian nerve

    Eur Radiol

    (2000)
  • L.E. Ginsberg et al.

    Greater superficial petrosal nerve: anatomy and MR findings in perineural tumor spread

    AJNR Am J Neuroradiol

    (1996)
  • I.M. Schmalfuss et al.

    Perineural tumor spread along the auriculotemporal nerve

    AJNR Am J Neuroradiol

    (2002)
  • V.F. Chong et al.

    Hypoglossal nerve palsy in nasopharyngeal carcinoma

    Eur Radiol

    (1998)
  • B.N. Streams et al.

    Perineural spread of squamous cell carcinoma involving the spinal accessory nerve in an immunocompromised organ transplant recipient

    Dermatol Surg

    (2005)
  • L.E. Ginsberg et al.

    Great auricular nerve: anatomy and imaging in a case of perineural tumor spread

    AJNR Am J Neuroradiol

    (2000)
  • S.H. Erbay et al.

    Nerve atrophy in severe trigeminal neuralgia: noninvasive confirmation at MR imaging–initial experience

    Radiology

    (2006)
  • C.H. Lau et al.

    The eye in malignant disease

    Hosp Med

    (2003)
  • R.H. Boerman et al.

    Trigeminal neuropathy secondary to perineural invasion of head and neck carcinomas

    Neurology

    (1999)
  • J.B. Bridgman et al.

    Facial sensory loss—a need for suspicion

    N Z Dent J

    (1998)
  • M.L. Slavin et al.

    Squamous cell carcinoma of the pterygopalatine fossa (retroantral space)

    J Clin Neuroophthalmol

    (1986)

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