CLINICAL DATA: Seventeen-year-old female with history of vertigo and headaches, and outside MRI examination suggesting presence of right CP angle mass. Evaluate for possible epidermoid versus arachnoid cyst.
FINDINGS: Ventricles and sulci are appropriate for the patients stated age of 17 years. No midline shift or acute territorial infarction is present. The intracranial flow voids, cervicomedullary junction, and orbits are preserved. The paranasal sinuses and mastoid air cells are preserved.
There is a lesion within the right cerebellopontine angle which extends inferiorly to the right cerebellomedullary junction and superiorly to the cerebellomesencephalic junction. This lesion has an AP dimension of approximately 2.8 cm, a maximum width of approximately 1.5 cm and a maximum vertical dimension of approximately 2.4 cm. The lesion demonstrates heterogeneity on T2 and FLAIR signal sequences and demonstrates restricted diffusion. These findings are most consistent with an epidermoid lesion.