Lipoma of trigeminal nerve in a patient with severe trigeminal neuralgia

T1 coronal images show homogenous hyperintense lesion involving the right trigeminal nerve root (white arrows) in A and B and Meckel's cave (white arrow) in C as compared to normal left trigeminal nerve (black arrows) and Meckel's cave (yellow arrow). Axial T1 image also demonstrates the involvement of mandibular division in foramen ovale (white arrow) as compared to normal on left side (orange arrow) in D.

Perineural spread of basal cell carcinoma along the trigeminal nerve

Axial image

Postgadolinium axial T1 fat-saturated image shows a thickened maxillary nerve (thin arrow) curving toward the pterygopalatine fossa. There is also linear enhancement along the vidian nerve (dashed arrow) and the mandibular nerve (thick arrow) within foramen ovale.