CT and MRI diagnosis of facial nerve neuroma(report of 6 cases) / 中华放射学杂志

ABSTRACT

Objective To investigate the value of CT and MRI in diagnosing facial nerve neuroma. Methods The CT and MRI findings of facial nerve neuroma proved by surgery and pathology in 6 cases were retrospectively analysed. Results Four of the six facial nerve neuroma only affected intratemporal segment of facial nerve (labyrinthine segment 1, tympanic segment 2, mastoid and tympanic segment 1), one involved the cerebellopontine angle(CPA) cistern, internal anditory canal(IAC) and intratemporal segment and last one involved both the intratemporal segment and the intraparotid gland segment. The imaging manifestations of the tumor depended on its location and extension. On CT, the tumors of intratemporal segment showed enlargement and destruction of facial nerve canal, soft tissue mass in the middle ear and /or in the mastoid, erosion of the aterior surface of the petrous bone at the level of the geniculate ganglion fossa, and extension to the middle cranial fossas and intraparotid gland. One neuroma arising from IAC and cisternal segments demonstrated a mass in the CPA, widening of the IAC, enlargement of the labyrinthine segment of the facial nerve canal, and extension to geniculate ganglion fossa by CT and MRI. Conclusion CT and MRI are accurate to describe the extent and location of facial nerve neuroma. CT is better to demonstrate the osseous destruction in detail, whereas enhanced MRI evaluates the tumor itself more accurately.