Schwannoma, nos

    Also known as: neurilemmoma

    Clinical Features:

    • Benign subcutaneous tumor, most often seen in adults
    • Most common on the limbs and head and neck
    • Usually cured by simple excision, with rare recurrences
    • May be multiple in neurofibromatosis type II

    Histologic Features:

    • Round, encapsulated mass in the subcutaneous fat (rarely intradermal)
    • Classically biphasic, with Antoni A and Antoni B areas:
      • Antoni A:
        • More cellular
        • Tightly packed spindle cells with tapered, wavy nuclei
        • Verocay bodies: hypocellular area flanked on two sides by palisading cells
        • Occasional nuclear pleomorphism (a degenerative change) and mitoses can be seen. 
        • Hyalinization or dystrophic calcification may be present.
      • Antoni B:
        • More hypocellular
        • Scattered spindle or stellate cells in a myxoid background
        • Focal chronic inflammation
        • Small hyalinized blood vessels
        • Degenerative changes may include microcystic change and hemosiderin deposition.
    • S-100 is positive, in keeping with the Schwann cell origin.
    • Rare tumors with hybrid features of schwannoma and neurofibroma exist.

    Cases associated with this book:

  • Schwannoma
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: Dermpedia Teaching Collection
  • Schwannoma
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: Teaching Collection