J Korean Radiol Soc.
1992 Jun;28(3):345-351.
Intratemporal facial nerve neuromas and their mimics; CT and MR findings
Abstract
- CT and MR findings of nine cases with intratemporal facial nerve nouromas were described and compared with CT findings of 3 cases with facial nerve palsy and facial nerve canal erosion which may mimic facial nerve neuroma. The tympanic segment of the facial nerve was involved in 8 cases, mastoid segment in 7 cases and labyrinthine segment in 5 cases. The lesions were easily diagnosed with high resolution CT with bone algorythms by showing the expansion of bony structures along the course of the facial nerves. In 4 cases with large vertical segment tumors. Extensive destruction of mastoid air cells and external auditory canals posed difficulty in making a diagnosis. Two out of 5 cases with labyrinthine segment imvolvement were presented as middle cranial fossa masses. MRI with enhancement was performed in 4 cases and was useful in characterizing the lesion as a tumor with its superior sensitivity to enhancement. Three cases of facial neuroma-mimicking lesion including post-inflammatory perineural thickening. Perineural extension from parotid adenoidcystic carcinoma, and congenita: cholesteatoma showed irrgular erosion or mild expansion of the facial nerve canal which may be helpful for differential diagnosis from neuromas.