Meningiomas of the posterior fossa represent a heterogeneous group of tumors regarding difficulty of resection and functional outcome.
The aim of this review was to focus on tumors located mainly on the posterior surface of the petrous bone and threatening hearing and facial functions.
An anatomical classification was used to evaluate surgical outcome depending on the relationship of the tumor to the internal auditory meatus. The authors performed a retrospective chart review of 53 consecutive patients operated on for a posterior petrous bone meningioma in a tertiary referral center and a literature review. Tumors were classified in four groups according to the modified Desgeorges and Sterkers classification: posterior petrous (P; 17 tumors), meatus and internal auditory canal (M; 12 tumors), petrous apex without invasion of the internal auditory canal (A; 9 tumors), and cerebellopontine angle with invasion of the internal auditory canal (AMP; 15 tumors).
The facial function was preserved in 100% of P and A tumors, 75% of group M tumors, and 53% of AMP tumors. Hearing preservation was attempted only in P, A, and M groups where rates of serviceable hearing preservation were 82%, 80%, and 66%, respectively. The cumulative rate of hearing preservation for AMP tumors was 45% in our literature review. The increased facial morbidity associated with AMP tumors compared with other groups was also confirmed by the review of the literature.
In conclusion, this study shows that among posterior petrous bone meningiomas, tumors invading the internal auditory canal present with increased postoperative functional morbidity in spite of a tailored approach regarding dural insertion.