American Urological Association - Neurofibroma
- Extremely rare, occur in patients with neurofibromatosis I.
- GU is involved in ~20% in patients with neurofibromatosis.
- Bladder is most commonly involved in GU tract, and involvement can be extensive.
- Typically involves young patients (~1/3 pediatric patients); male>female (3:1).
- Mainly of plexiform type (involves multiple fascicles of nerve).
- Loose spindle cells with tapered wavy nuclei (image A).
- Associated with irregular collagen bundles ("shredded carrot" appearance) (image B).
- No nuclear atypia or mitosis.
- Immunohistochemistry: S100+.