Legend Axial T2WIs show a large, irregular, intermediate-signal mass at the left skull base, involving the left pterygoid muscles and the parapharygeal space. The tumor extends posteriorly along the course of the greater petrosal nerve and likely involves the geniculate ganglion and petrous apex. Hyperintense signal is noted in the left mastoid air cells and the petrous apex.

Legend Left: Sagittal T1WI shows the mass to have intermediate T1 signal. Punctate and linear hypointensities within the mass suggest increased vascularity. The mass extends into the middle fossa to compress the temporal lobe. Right: Axial and Coronal post contrast T1WIs reveal bright and mildly heterogeneous enhancement of the mass. The hyperintense mastoid and petrous air cells is due to enhancing membranes and proteinaceous fluid. Key words: mri skull base temporal bone facial nerve tumor neoplasia

ENT Diagnosis: Malignant schwannoma of the 7th (facial) cranial nerve