Subarachnoid fat embolism complicating autologous fat grafting following translabyrinthine excision of acoustic neuroma.

A 64-year-old man had complete excision of an acoustic schwannoma via the translabyrinthine route and the mastoid cavity was packed with fat. Post-operatively there were two episodes of aseptic meningitis and CT scanning demonstrated migration of fat into the basal subarachnoid CSF spaces. This unusual complication should be recognized and differentiated from both true infective meningitis and aseptic meningitis from other causes.