Incidence, Clinico-Radiological Features and Outcome of Skull Base versus Non-Skull Base Meningiomas Treated in Kuala Lumpur General Hospital: A Five-Year Experience

Background: Meningiomas are the most common intracranial tumours; they account for 13%-26% of all the primary intracranial tumours. Skull base meningiomas make up 25% of all meningiomas and are one of the most difficult intracranial tumours to be managed surgically. This is due to the fact that it is difficult to approach the lesions which are also close to vital structures such as cranial nerves and major blood vessels. Despite the abundance of these cases in Malaysia, local data on meningiomas is scarce.

Methods: This is a retrospective study consisting of 199 patients with meningiomas who have been operated at the Kuala Lumpur General Hospital from January 2010-December 2014. They were categorised into skull base and non-skull base groups. Demography, tumour characteristics, and patient outcomes were analysed. Kaplan-Meier survival curves as well as Cox hazard univariable and multivariable regressions for the possible predictors of survival were analysed.

Results: 97.5% of the patients (n = 194) had WHO grade I meningioma and only five patients had WHO grade II meningioma. There was a female predominance (n = 134; 67.3%), with a male-to-female ratio of 1:2. Some 27.1 % patients had skull base meningiomas. Patients with skull base meningiomas had poorer outcomes and discharge conditions (n = 23; 42.6% P < 0.01), in addition to higher risk of incomplete resections (n = 34; 63% P < 0.01). Multivariate cox hazard regressions showed that the skull base meningioma group had four times the risk of death of the non-skull base group.

Conclusions: Symptomatic meningiomas can be curative if the tumour is completely removed. Our study has revealed that skull base meningiomas which were operated locally had higher rates of incomplete resection and poorer surgical outcomes as compared to the non-skull base group. Patients with skull base meningiomas had four times the risk of death vis-à-vis non-skull base ones. More local studies are needed to look into skull base meningiomas for the improvement of its surgical outcomes.