Feeling Twitchy

Question:  A 29 year old female presents with hemifacial spasm of 3 months duration.  She lost the hearing in that ear 6 months previously and was treated with steroids for presumed idiopathic sudden sensorineural hearing loss.  MRI revealed a lesion in the distal internal auditory canal.  She undergoes a translabyrinthine approach to the IAC upon which a vascular mass is discovered.  What is the diagnosis?  [Answer will be posted with next week's new question]

Answer to last week's question, "It's All In The Genes" (May 2, 2016): 

E6 and E7.