Acoustic Neuroma

FACTS

 

HPI

 

PHYSICAL EXAM

IMAGING

Koss Grades
1: intracanalicular
2: minimal tumor extension into CPA < 2cm
3: occipies CPA but not displacing cerebellar trunk <3cm
4: large tumor w/ brainstem displacement > 3cm
NOTE:  acoustics usually displace the facial nerve VENTRALLY as the facial nerve enters facial canal anterior suprerior quadrant of meatus
Internal Acoustic Meatus Facial Nerve
A/P
GKRS
  • 4% rate facial neuropathy
  • 60% hearing preservation at margin 12-13 Gy, the lower the dose to cochlea the better
  • takes weeks to months/1 year to show any effect

Pathology

Figure 1: Pathology features: S100 positive and biphasic, eliciting compact hypercellular Antoni A areas and myxoid hypocellular Antoni B areas. Cells are narrow and elongated with wavy with tapered ends and interspersed with collagen fibers. Verocay bodies, or nuclear palisading around a fibrillary process, can be seen in cellular areas.