Go Back Brain/12. Base of skull/Neoplasm, Neoplasm-like condition/12.3 - Perineural Tumor Spread/ Go to Index

78 year old male with double vision.

Meningioma

Schwannoma

Inflammatory -- Tolosa-Hunt

Lymphoma

Metastasis

Infection

Thrombosis

Vascular -- CCF, aneurysm.

Any malignancy may demonstrate PNT

Adenoid cystic carcinoma

“path of least resistance” as local tumor enlarges in size

Can extend antegrade or retrograde

May be non-contiguous -- “skip lesions”

Poor prognostic indicator.

Cranial Nerve V3

Malignant source

Skin of chin and jaw (SCCa or melanoma)

Masticator space or alveolar ridge SCCA

Masticator space Non-Hodgkin lymphoma

Parotid malignancy via auriculotemporal branch of V3

Enlargement/enhancement of nerve complex -- preganglionic (cisternal) segment, Meckel’s cave, foramen ovale, V3 mandibular branch, inferior alveolar nerve

May be asymptomatic (40%); jaw pain, facial paresthesias, masticator muscle atrophy

DDX -- pterygoid venous plexus, vasa nervosa of V3, schwannoma, meningioma.

Cranial Nerve VII

Malignant source most commonly arises from parotid gland

Abnormal enlargement and enhancement of infratemporal facial nerve extending through stylomastoid foramen to involve mastoid segment

May extend to root exit zone in CPA

May be asymptomatic (60%); facial nerve paralysis

DDX -- Bell’s palsy, schwannoma.