Meningiomas primarily originate from arachnoid cap cells. The incidence rate of meningiomas is approximately 2 per 100,000 people, making it the second most common tumor in the cerebellopontine angle region, accounting for 6% to 8% of cases. In recent years, the incidence of meningiomas has significantly increased, particularly in middle-aged and elderly populations, due to advancements and widespread use of CT and MRI technology. Females are more frequently affected than males, with a ratio of approximately 2:1.
Meningiomas of the cerebellopontine angle commonly present with dysfunction of the fifth (trigeminal), seventh (facial), and eighth (vestibulocochlear) cranial nerves, as well as cerebellar dysfunction. In cases of larger tumors, increased intracranial pressure may also occur. Hearing impairment is the most frequent symptom of vestibulocochlear nerve involvement, affecting over 90% of patients, along with early-onset tinnitus. Vertigo is relatively uncommon. Facial nerve involvement may result in muscle twitching or mild facial paralysis. Trigeminal nerve damage can manifest as facial numbness, sensory loss, loss of the corneal reflex, and muscle atrophy in the masseter and other masticatory muscles.
Cerebellar compression may lead to symptoms such as gait instability, coarse horizontal nystagmus, and ataxia.
Distinguishing cerebellopontine angle meningiomas from vestibular schwannomas (acoustic neuromas) involves several factors: (1) Meningiomas are more common in females, whereas vestibular schwannomas are more frequently observed in males; (2) Vestibular dysfunction is less common in meningiomas but more frequently accompanied by trigeminal and facial nerve dysfunction in vestibular schwannomas; (3) On imaging, meningiomas often appear crescent-shaped, whereas vestibular schwannomas are usually round. The angle between the tumor and the petrous bone is generally obtuse in meningiomas but acute in vestibular schwannomas. Enlargement of the internal auditory canal is a characteristic feature of vestibular schwannomas. Calcification occurs in approximately 25% of meningiomas, and the presence of calcification strongly suggests meningiomas.
Surgical resection is the most effective treatment for meningiomas.