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: DermatopathologyConsultations.com Teaching Collection