The differential diagnosis of cerebellopontine angle masses include vestibular schwannoma (most common), meningioma, and epidermoid cyst. This patient had the mass excised.

Histopathology

Microscopic description: The sections show a moderately cellular meningioma. The tumor forms whorls. No sheeting arrangement is seen. The tumor cells have ovoid nuclei with no nuclear pleomorphism. Mitoses are inconspicuous. There is no necrosis. No brain parenchyma is present. No evidence of atypical or malignant change is identified.

Final diagnosis: Left cerebellopontine angle tumor: meningioma (WHO grade I).

This is centered is centered posteriorly to the internal acoustic meatus, and has imaging characteristics that are characteristic of a meningioma.