Exophytic pontine glioma mimicking acoustic neurinoma: CT and MRI appearance.

A 31-year-old female having a family history of neurofibromatosis 1 presented a left CPA tumor. MRI findings showed a completely extraaxial tumor, suggesting an acoustic neurinoma except for the lesion in the acoustic meatus. However, the final diagnosis was of exophytic pontine glioma. When a CPA tumor shows no lesion in the internal acoustic meatus, the possibility of exophytic pontine glioma should be considered in the differential diagnosis, especially in NF-1 patients.