6.3.6: 6. Imaging
- Page ID
- 18312
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Minority of parotid tumours require imaging
- Only required if it might change management
- Infrequently indicated for clinically benign, mobile parotid tumours as it rarely alters surgical management
Indications
- Suspect non-neoplastic disease e.g. HIV lymphoepithelial cyst, TB, benign cyst, lipoma (US / CT)
- Deep vs superficial lobe parotid tumour
- Mobile tumour: Only if surgeon does not have skill to resect a deep lobe tumour (CT with contrast / MRI)
- Reduced mobility/fixed tumour
- Deep lobe tumour (CT with contrast / MRI)
- Extension to parapharyngeal space (CT with contrast / MRI)
- Invasion of local structures (CT / MRI)
- Recurrence of benign or malignant tumours (MRI)
- Neurological deficits e.g. facial nerve to determine extent of perineural invasion (MRI with Gd)
- Metastases to parotid gland (skin, conjunctiva), to plan selective vs therapeutic neck dissection (US / CT / MRI)
- Exclude lung metastases with suspected/known malignancy (CXR / CT)
Types of imaging
- Ultrasound
- Cystic vs solid; associated cervical lymph nodes
- Not good for deep vs superficial lobe, or for parapharyngeal extension
- CT with contrast
- Cystic vs solid; associated cervical lymph nodes
- Deep vs superficial lobe mass, or for parapharyngeal extension (Need to identify retromandibular vein (Need to identify retromandibular vein)
- MRI
- Tumour “stuck” around stylomastoid foramen area
- Local invasion (Good soft tissue differentiation)
- Deep vs superficial lobe mass, or for parapharyngeal extension
- Perineural invasion
PET-CT: Unhelpful as benign pathology (pleomorphic adenoma, Warthin tumours, TB, abscesses, lymphoma) are PET-avid