•MRI and PET CT plays crucial role is early identification of perineural spread.•This exhibit demonstrates pathway of PNTS and explains the direct and indirect imaging findings of PNTS.•Direct: Abnormalities of the nerve and adjacent structures.•Indirect: Muscular asymmetry due to denervation atrophy.•Early imaging finding- Loss of the fat attenuation in the neural foramen or expected neural pathway•Late imaging finding- Asymmetric enlargement of the nerve pathway filled by soft tissue mass and erosion of the adjacent bone.
Case 1: FDG PET CT: 35 years,
male.
Right buccal carcinoma.
• Large ulcerative heterogeneously enhancing metabolically active mass lesion in the right gingivo-buccal sulcus extending to the retromolar trigone and infratemporal fossa.
Permeative destruction of the right hemimandible with periosteal reaction and widening of the inferior alveolar nerve canal,
suggestive of perineural tumor spread.
Case 2: MRI T1 contrast: 53 years,
male.
• Carcinoma palate with spread along the maxillary division of trigeminal nerve.
Case 3: FDG PET CT: 56 years,
male.
• Carcinoma palate with spread along the right inferior alveolar nerve
Case 4: FDG PET CT: 60 years male
Carcinoma left retromolar trigone with spread along the left foramen ovale
Case 5: MRI coronal T1 contrast: 63 years,
male.
Carcinoma palate with spread in left mandibular nerve.
Case 6: MRI coronal T1 contrast: 57 years,
male.
Carcinoma left buccal mucosa with enhancement along the left inferior alveolar nerve
Case 7: Carcinoma right RMT and buccal mucosa,
post operative and post chemotherapy.
• T2 / STIR hyper intensity in right upper lateral pharyngeal wall and right masticatory space – likely representing post operative residual edema.
• T2 / STIR hyper intensity involving the right parotid and retromandibular region with few irregular foci of hyper intensity and corresponding diffusion restriction and heterogeneous post contrast enhancement – likely representing recurrent disease.
• Focal heterogeneous mildly hyper intense soft tissue along the medial aspect of the right ICA in right retropharyngeal space,
possibly involving the right hypoglossal nerve.
• Hyperintensity and enhancement of right half of the tongue- Subacute phase of denervation of hypoglossal nerve
Case 8:
• Operated case of carcinoma left buccal mucosa with local recurrence
• Interval left hemimandibulectomy,
resection of the buccal mucosa,
radical left neck lymph nodal dissection with osseous and myocutaneous reconstruction of the left cheek.
• Post contrast screening of the upper neck shows irregular enhancing soft tissue mass lesion in the surrounding the bone graft,
left infra-temporal fossa,
the parapharyngeal space,
encasing and narrowing of the left ECA and proximal ICA.
• Postero-superiorly,
the lesion is extending upto the stylomastoid foramen with thickening and enhancement of the facial nerve extending upto the anterior genu – suggestive of perineural extension.