Histology Course A IV 34 Department of Pathology, University of Zurich Histokurs

A IV 34

neurilemoma (synonym: schwannoma) HE further information (German) on HiPaKu 
  ICD-10: D36.1; ICD-O: 9560/0
 
   
43-year-old female had a painful subcutaneous tumor (surgical resection specimen).
 
- Circumscribed tumor consisting of spindle cells with fusiform nuclei.
- In some areas closely packed cells growing in a fasciculated or whorled pattern (Antoni A pattern). Some nuclei form orderly palisades (Verrocay bodies).
- In other areas loosely packed, haphazardly arranged elongated cells in a myxoid stroma (Antoni B pattern).
- Between tumor cells fine fibers arranged in parallel are observed.
- Some vessels show a hyalinized wall and the stroma is focally hyalinized (so called ancient change)

 
Occurrence:
- Peripheral nerves
- Spinal nerve roots
- Cranial nerves: e.g. vestibular schwannoma.
- Autonomic nervous system.

Bilateral vestibular schwannomas are commonly found in patients with neurofibromatosis Type 2. In addition, these patients develop schwannomas of other cranial and peripheral nerves and have a predisposition to develop meningeomas and gliomas.

Immunohistochemistry:
Tumors are diffusely positive for S-100.