Schwannoma (Neurilemmoma)

Schwannoma (Neurilemmoma)

Amitabh Srivastava, MD

Schwannomas are well-circumscribed, encapsulated tumors and often arise as an eccentric mass loosely attached to an underlying nerve. The underlying nerve image wraps around the tumor in this example.

Schwannomas are composed of alternating hypercellular spindle cell areas (Antoni A image) and hypocellular round cell areas (Antoni B image). Nuclear palisading is often present in Antoni A areas.



  • Encapsulated, benign peripheral nerve sheath tumor composed predominantly of Schwann cells


Molecular Aberrations

  • Somatic NF2 gene mutations present in most tumors

  • Bilateral vestibular schwannomas occur in setting of germline NF2 gene mutations



  • Incidence

    • 90% are sporadic

    • 10% are syndromic

      • About 3% with neurofibromatosis type 2 (NF2)

      • 2% with schwannomatosis

      • 5% with multiple meningiomas

      • Rarely in association with neurofibromatosis type 1 (NF1)

  • Age

    • All ages

    • Common between 20-50 years of age

  • Gender

    • Affects males and females equally


  • Head & neck

  • Upper and lower extremities

  • Deep-seated tumors occur in mediastinum and retroperitoneum


  • Slow growing

  • Painless mass in most cases

    • Large tumors may be painful

  • Cystic tumors may show fluctuation in size


  • Surgical excision is curative


  • Excellent

Multiple Schwannoma Syndromes

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Schwannoma (Neurilemmoma)

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